84 files changed, 1121 insertions, 413 deletions

diff --git a/src/core/ext/census/gen/trace_context.pb.h b/src/core/ext/census/gen/trace_context.pb.h
index ea127bf70a..6fafc04c81 100644
--- a/src/core/ext/census/gen/trace_context.pb.h
+++ b/src/core/ext/census/gen/trace_context.pb.h
@@ -90,4 +90,4 @@ extern const pb_field_t google_trace_TraceContext_fields[5];
 #endif
 /* @@protoc_insertion_point(eof) */
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_GEN_TRACE_CONTEXT_PB_H */
diff --git a/src/core/ext/census/grpc_filter.c b/src/core/ext/census/grpc_filter.c
index fc29dbd454..bcf59a4efe 100644
--- a/src/core/ext/census/grpc_filter.c
+++ b/src/core/ext/census/grpc_filter.c
@@ -74,17 +74,18 @@ static void extract_and_annotate_method_tag(grpc_metadata_batch *md,
 }
 
 static void client_mutate_op(grpc_call_element *elem,
-                             grpc_transport_stream_op *op) {
+                             grpc_transport_stream_op_batch *op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   if (op->send_initial_metadata) {
-    extract_and_annotate_method_tag(op->send_initial_metadata, calld, chand);
+    extract_and_annotate_method_tag(
+        op->payload->send_initial_metadata.send_initial_metadata, calld, chand);
   }
 }
 
 static void client_start_transport_op(grpc_exec_ctx *exec_ctx,
                                       grpc_call_element *elem,
-                                      grpc_transport_stream_op *op) {
+                                      grpc_transport_stream_op_batch *op) {
   client_mutate_op(elem, op);
   grpc_call_next_op(exec_ctx, elem, op);
 }
@@ -103,19 +104,22 @@ static void server_on_done_recv(grpc_exec_ctx *exec_ctx, void *ptr,
 }
 
 static void server_mutate_op(grpc_call_element *elem,
-                             grpc_transport_stream_op *op) {
+                             grpc_transport_stream_op_batch *op) {
   call_data *calld = elem->call_data;
   if (op->recv_initial_metadata) {
     /* substitute our callback for the op callback */
-    calld->recv_initial_metadata = op->recv_initial_metadata;
-    calld->on_done_recv = op->recv_initial_metadata_ready;
-    op->recv_initial_metadata_ready = &calld->finish_recv;
+    calld->recv_initial_metadata =
+        op->payload->recv_initial_metadata.recv_initial_metadata;
+    calld->on_done_recv =
+        op->payload->recv_initial_metadata.recv_initial_metadata_ready;
+    op->payload->recv_initial_metadata.recv_initial_metadata_ready =
+        &calld->finish_recv;
   }
 }
 
 static void server_start_transport_op(grpc_exec_ctx *exec_ctx,
                                       grpc_call_element *elem,
-                                      grpc_transport_stream_op *op) {
+                                      grpc_transport_stream_op_batch *op) {
   /* TODO(ctiller): this code fails. I don't know why. I expect it's
                     incomplete, and someone should look at it soon.
 
diff --git a/src/core/ext/census/grpc_plugin.c b/src/core/ext/census/grpc_plugin.c
index c9fe453af8..7d0c9f14ae 100644
--- a/src/core/ext/census/grpc_plugin.c
+++ b/src/core/ext/census/grpc_plugin.c
@@ -31,6 +31,8 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
 #include <limits.h>
 #include <string.h>
 
@@ -48,7 +50,7 @@ static bool is_census_enabled(const grpc_channel_args *a) {
       return a->args[i].value.integer != 0 && census_enabled();
     }
   }
-  return census_enabled();
+  return census_enabled() && !grpc_channel_args_want_minimal_stack(a);
 }
 
 static bool maybe_add_census_filter(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/census/trace_label.h b/src/core/ext/census/trace_label.h
index 0e4a8d885f..701f6f5a63 100644
--- a/src/core/ext/census/trace_label.h
+++ b/src/core/ext/census/trace_label.h
@@ -58,4 +58,4 @@ typedef struct trace_label {
   } value;
 } trace_label;
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_LABEL_H */
diff --git a/src/core/ext/census/trace_propagation.h b/src/core/ext/census/trace_propagation.h
index 75c4ebaa39..0c27bfa111 100644
--- a/src/core/ext/census/trace_propagation.h
+++ b/src/core/ext/census/trace_propagation.h
@@ -60,4 +60,4 @@ size_t trace_span_context_to_http_format(const trace_span_context *ctxt,
 size_t http_format_to_trace_span_context(const char *buf, size_t buf_size,
                                          trace_span_context *ctxt);
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_PROPAGATION_H */
diff --git a/src/core/ext/census/trace_status.h b/src/core/ext/census/trace_status.h
index adc0ebd0c0..0734ec6d3d 100644
--- a/src/core/ext/census/trace_status.h
+++ b/src/core/ext/census/trace_status.h
@@ -42,4 +42,4 @@ typedef struct trace_status {
   trace_string errorMessage;
 } trace_status;
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_STATUS_H */
diff --git a/src/core/ext/census/trace_string.h b/src/core/ext/census/trace_string.h
index 8e77ee9f7e..cd63cfb92f 100644
--- a/src/core/ext/census/trace_string.h
+++ b/src/core/ext/census/trace_string.h
@@ -47,4 +47,4 @@ typedef struct trace_string {
   size_t length;
 } trace_string;
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_TRACE_STRING_H */
diff --git a/src/core/ext/census/tracing.h b/src/core/ext/census/tracing.h
index c2b947ae40..3a7c6f45e4 100644
--- a/src/core/ext/census/tracing.h
+++ b/src/core/ext/census/tracing.h
@@ -121,4 +121,4 @@ free to ignore all further calls using the Span. EndSpanOptions can
 optionally be NULL. */
 void trace_end_span(const trace_status *status, trace_span_context *span_ctxt);
 
-#endif
+#endif /* GRPC_CORE_EXT_CENSUS_TRACING_H */
diff --git a/src/core/ext/client_channel/README.md b/src/core/ext/filters/client_channel/README.md
index 7c209db12e..7c209db12e 100644
--- a/src/core/ext/client_channel/README.md
+++ b/src/core/ext/filters/client_channel/README.md
diff --git a/src/core/ext/client_channel/channel_connectivity.c b/src/core/ext/filters/client_channel/channel_connectivity.c
index f6cb3b9115..62f58fb278 100644
--- a/src/core/ext/client_channel/channel_connectivity.c
+++ b/src/core/ext/filters/client_channel/channel_connectivity.c
@@ -36,7 +36,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/completion_queue.h"
diff --git a/src/core/ext/client_channel/client_channel.c b/src/core/ext/filters/client_channel/client_channel.c
index 435a3ab0fe..83e3b8f118 100644
--- a/src/core/ext/client_channel/client_channel.c
+++ b/src/core/ext/filters/client_channel/client_channel.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
 
 #include <stdbool.h>
 #include <stdio.h>
@@ -43,12 +43,12 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/useful.h>
 
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/proxy_mapper_registry.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
-#include "src/core/ext/client_channel/retry_throttle.h"
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/retry_throttle.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/channel/deadline_filter.h"
@@ -374,8 +374,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
     // resolver actually specified.
     channel_arg =
         grpc_channel_args_find(chand->resolver_result, GRPC_ARG_LB_ADDRESSES);
-    if (channel_arg != NULL) {
-      GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
+    if (channel_arg != NULL && channel_arg->type == GRPC_ARG_POINTER) {
       grpc_lb_addresses *addresses = channel_arg->value.pointer.p;
       bool found_backend_address = false;
       for (size_t i = 0; i < addresses->num_addresses; ++i) {
@@ -533,7 +532,7 @@ static void on_resolver_result_changed_locked(grpc_exec_ctx *exec_ctx,
 static void start_transport_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                       grpc_error *error_ignored) {
   grpc_transport_op *op = arg;
-  grpc_channel_element *elem = op->transport_private.args[0];
+  grpc_channel_element *elem = op->handler_private.extra_arg;
   channel_data *chand = elem->channel_data;
 
   if (op->on_connectivity_state_change != NULL) {
@@ -595,12 +594,12 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx,
                                  op->bind_pollset);
   }
 
-  op->transport_private.args[0] = elem;
+  op->handler_private.extra_arg = elem;
   GRPC_CHANNEL_STACK_REF(chand->owning_stack, "start_transport_op");
   grpc_closure_sched(
-      exec_ctx, grpc_closure_init(
-                    &op->transport_private.closure, start_transport_op_locked,
-                    op, grpc_combiner_scheduler(chand->combiner, false)),
+      exec_ctx,
+      grpc_closure_init(&op->handler_private.closure, start_transport_op_locked,
+                        op, grpc_combiner_scheduler(chand->combiner, false)),
       GRPC_ERROR_NONE);
 }
 
@@ -643,14 +642,26 @@ static grpc_error *cc_init_channel_elem(grpc_exec_ctx *exec_ctx,
   // Record client channel factory.
   const grpc_arg *arg = grpc_channel_args_find(args->channel_args,
                                                GRPC_ARG_CLIENT_CHANNEL_FACTORY);
-  GPR_ASSERT(arg != NULL);
-  GPR_ASSERT(arg->type == GRPC_ARG_POINTER);
+  if (arg == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Missing client channel factory in args for client channel filter");
+  }
+  if (arg->type != GRPC_ARG_POINTER) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "client channel factory arg must be a pointer");
+  }
   grpc_client_channel_factory_ref(arg->value.pointer.p);
   chand->client_channel_factory = arg->value.pointer.p;
   // Get server name to resolve, using proxy mapper if needed.
   arg = grpc_channel_args_find(args->channel_args, GRPC_ARG_SERVER_URI);
-  GPR_ASSERT(arg != NULL);
-  GPR_ASSERT(arg->type == GRPC_ARG_STRING);
+  if (arg == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Missing server uri in args for client channel filter");
+  }
+  if (arg->type != GRPC_ARG_STRING) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "server uri arg must be a string");
+  }
   char *proxy_name = NULL;
   grpc_channel_args *new_args = NULL;
   grpc_proxy_mappers_map_name(exec_ctx, arg->value.string, args->channel_args,
@@ -755,7 +766,7 @@ typedef struct client_channel_call_data {
   grpc_connected_subchannel *connected_subchannel;
   grpc_polling_entity *pollent;
 
-  grpc_transport_stream_op **waiting_ops;
+  grpc_transport_stream_op_batch **waiting_ops;
   size_t waiting_ops_count;
   size_t waiting_ops_capacity;
 
@@ -775,7 +786,8 @@ grpc_subchannel_call *grpc_client_channel_get_subchannel_call(
   return scc == CANCELLED_CALL ? NULL : scc;
 }
 
-static void add_waiting_locked(call_data *calld, grpc_transport_stream_op *op) {
+static void add_waiting_locked(call_data *calld,
+                               grpc_transport_stream_op_batch *op) {
   GPR_TIMER_BEGIN("add_waiting_locked", 0);
   if (calld->waiting_ops_count == calld->waiting_ops_capacity) {
     calld->waiting_ops_capacity = GPR_MAX(3, 2 * calld->waiting_ops_capacity);
@@ -791,7 +803,7 @@ static void fail_locked(grpc_exec_ctx *exec_ctx, call_data *calld,
                         grpc_error *error) {
   size_t i;
   for (i = 0; i < calld->waiting_ops_count; i++) {
-    grpc_transport_stream_op_finish_with_failure(
+    grpc_transport_stream_op_batch_finish_with_failure(
         exec_ctx, calld->waiting_ops[i], GRPC_ERROR_REF(error));
   }
   calld->waiting_ops_count = 0;
@@ -804,7 +816,7 @@ static void retry_waiting_locked(grpc_exec_ctx *exec_ctx, call_data *calld) {
   }
 
   grpc_subchannel_call *call = GET_CALL(calld);
-  grpc_transport_stream_op **ops = calld->waiting_ops;
+  grpc_transport_stream_op_batch **ops = calld->waiting_ops;
   size_t nops = calld->waiting_ops_count;
   if (call == CANCELLED_CALL) {
     fail_locked(exec_ctx, calld, GRPC_ERROR_CANCELLED);
@@ -902,14 +914,14 @@ static void subchannel_ready_locked(grpc_exec_ctx *exec_ctx, void *arg,
         .arena = calld->arena};
     grpc_error *new_error = grpc_connected_subchannel_create_call(
         exec_ctx, calld->connected_subchannel, &call_args, &subchannel_call);
+    gpr_atm_rel_store(&calld->subchannel_call,
+                      (gpr_atm)(uintptr_t)subchannel_call);
     if (new_error != GRPC_ERROR_NONE) {
       new_error = grpc_error_add_child(new_error, error);
-      subchannel_call = CANCELLED_CALL;
       fail_locked(exec_ctx, calld, new_error);
+    } else {
+      retry_waiting_locked(exec_ctx, calld);
     }
-    gpr_atm_rel_store(&calld->subchannel_call,
-                      (gpr_atm)(uintptr_t)subchannel_call);
-    retry_waiting_locked(exec_ctx, calld);
   }
   GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_subchannel");
 }
@@ -1052,9 +1064,9 @@ static bool pick_subchannel_locked(
   return false;
 }
 
-static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
-                                                   grpc_transport_stream_op *op,
-                                                   grpc_call_element *elem) {
+static void start_transport_stream_op_batch_locked_inner(
+    grpc_exec_ctx *exec_ctx, grpc_transport_stream_op_batch *op,
+    grpc_call_element *elem) {
   channel_data *chand = elem->channel_data;
   call_data *calld = elem->call_data;
   grpc_subchannel_call *call;
@@ -1062,7 +1074,7 @@ static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
   /* need to recheck that another thread hasn't set the call */
   call = GET_CALL(calld);
   if (call == CANCELLED_CALL) {
-    grpc_transport_stream_op_finish_with_failure(
+    grpc_transport_stream_op_batch_finish_with_failure(
         exec_ctx, op, GRPC_ERROR_REF(calld->cancel_error));
     /* early out */
     return;
@@ -1073,11 +1085,11 @@ static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
     return;
   }
   /* if this is a cancellation, then we can raise our cancelled flag */
-  if (op->cancel_error != GRPC_ERROR_NONE) {
+  if (op->cancel_stream) {
     if (!gpr_atm_rel_cas(&calld->subchannel_call, 0,
                          (gpr_atm)(uintptr_t)CANCELLED_CALL)) {
       /* recurse to retry */
-      start_transport_stream_op_locked_inner(exec_ctx, op, elem);
+      start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem);
       /* early out */
       return;
     } else {
@@ -1086,27 +1098,29 @@ static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
          cancelled before any ops are passed down (e.g., if the deadline
          is in the past when the call starts), we can return the right
          error to the caller when the first op does get passed down. */
-      calld->cancel_error = GRPC_ERROR_REF(op->cancel_error);
+      calld->cancel_error =
+          GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error);
       switch (calld->creation_phase) {
         case GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING:
-          fail_locked(exec_ctx, calld, GRPC_ERROR_REF(op->cancel_error));
+          fail_locked(exec_ctx, calld,
+                      GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error));
           break;
         case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL:
-          pick_subchannel_locked(exec_ctx, elem, NULL, 0,
-                                 &calld->connected_subchannel, NULL,
-                                 GRPC_ERROR_REF(op->cancel_error));
+          pick_subchannel_locked(
+              exec_ctx, elem, NULL, 0, &calld->connected_subchannel, NULL,
+              GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error));
           break;
       }
-      grpc_transport_stream_op_finish_with_failure(
-          exec_ctx, op, GRPC_ERROR_REF(op->cancel_error));
+      grpc_transport_stream_op_batch_finish_with_failure(
+          exec_ctx, op,
+          GRPC_ERROR_REF(op->payload->cancel_stream.cancel_error));
       /* early out */
       return;
     }
   }
   /* if we don't have a subchannel, try to get one */
   if (calld->creation_phase == GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING &&
-      calld->connected_subchannel == NULL &&
-      op->send_initial_metadata != NULL) {
+      calld->connected_subchannel == NULL && op->send_initial_metadata) {
     calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL;
     grpc_closure_init(&calld->next_step, subchannel_ready_locked, elem,
                       grpc_combiner_scheduler(chand->combiner, true));
@@ -1114,10 +1128,11 @@ static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
     /* If a subchannel is not available immediately, the polling entity from
        call_data should be provided to channel_data's interested_parties, so
        that IO of the lb_policy and resolver could be done under it. */
-    if (pick_subchannel_locked(exec_ctx, elem, op->send_initial_metadata,
-                               op->send_initial_metadata_flags,
-                               &calld->connected_subchannel, &calld->next_step,
-                               GRPC_ERROR_NONE)) {
+    if (pick_subchannel_locked(
+            exec_ctx, elem,
+            op->payload->send_initial_metadata.send_initial_metadata,
+            op->payload->send_initial_metadata.send_initial_metadata_flags,
+            &calld->connected_subchannel, &calld->next_step, GRPC_ERROR_NONE)) {
       calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
       GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "pick_subchannel");
     } else {
@@ -1137,16 +1152,16 @@ static void start_transport_stream_op_locked_inner(grpc_exec_ctx *exec_ctx,
         .arena = calld->arena};
     grpc_error *error = grpc_connected_subchannel_create_call(
         exec_ctx, calld->connected_subchannel, &call_args, &subchannel_call);
+    gpr_atm_rel_store(&calld->subchannel_call,
+                      (gpr_atm)(uintptr_t)subchannel_call);
     if (error != GRPC_ERROR_NONE) {
-      subchannel_call = CANCELLED_CALL;
       fail_locked(exec_ctx, calld, GRPC_ERROR_REF(error));
-      grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
+      grpc_transport_stream_op_batch_finish_with_failure(exec_ctx, op, error);
+    } else {
+      retry_waiting_locked(exec_ctx, calld);
+      /* recurse to retry */
+      start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem);
     }
-    gpr_atm_rel_store(&calld->subchannel_call,
-                      (gpr_atm)(uintptr_t)subchannel_call);
-    retry_waiting_locked(exec_ctx, calld);
-    /* recurse to retry */
-    start_transport_stream_op_locked_inner(exec_ctx, op, elem);
     /* early out */
     return;
   }
@@ -1174,15 +1189,16 @@ static void on_complete(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
                    GRPC_ERROR_REF(error));
 }
 
-static void start_transport_stream_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
-                                             grpc_error *error_ignored) {
-  GPR_TIMER_BEGIN("start_transport_stream_op_locked", 0);
+static void start_transport_stream_op_batch_locked(grpc_exec_ctx *exec_ctx,
+                                                   void *arg,
+                                                   grpc_error *error_ignored) {
+  GPR_TIMER_BEGIN("start_transport_stream_op_batch_locked", 0);
 
-  grpc_transport_stream_op *op = arg;
-  grpc_call_element *elem = op->handler_private.args[0];
+  grpc_transport_stream_op_batch *op = arg;
+  grpc_call_element *elem = op->handler_private.extra_arg;
   call_data *calld = elem->call_data;
 
-  if (op->recv_trailing_metadata != NULL) {
+  if (op->recv_trailing_metadata) {
     GPR_ASSERT(op->on_complete != NULL);
     calld->original_on_complete = op->on_complete;
     grpc_closure_init(&calld->on_complete, on_complete, elem,
@@ -1190,11 +1206,11 @@ static void start_transport_stream_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
     op->on_complete = &calld->on_complete;
   }
 
-  start_transport_stream_op_locked_inner(exec_ctx, op, elem);
+  start_transport_stream_op_batch_locked_inner(exec_ctx, op, elem);
 
   GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call,
-                        "start_transport_stream_op");
-  GPR_TIMER_END("start_transport_stream_op_locked", 0);
+                        "start_transport_stream_op_batch");
+  GPR_TIMER_END("start_transport_stream_op_batch_locked", 0);
 }
 
 /* The logic here is fairly complicated, due to (a) the fact that we
@@ -1205,39 +1221,40 @@ static void start_transport_stream_op_locked(grpc_exec_ctx *exec_ctx, void *arg,
    We use double-checked locking to initially see if initialization has been
    performed. If it has not, we acquire the combiner and perform initialization.
    If it has, we proceed on the fast path. */
-static void cc_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
-                                         grpc_call_element *elem,
-                                         grpc_transport_stream_op *op) {
+static void cc_start_transport_stream_op_batch(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_transport_stream_op_batch *op) {
   call_data *calld = elem->call_data;
   channel_data *chand = elem->channel_data;
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
-  grpc_deadline_state_client_start_transport_stream_op(exec_ctx, elem, op);
+  grpc_deadline_state_client_start_transport_stream_op_batch(exec_ctx, elem,
+                                                             op);
   /* try to (atomically) get the call */
   grpc_subchannel_call *call = GET_CALL(calld);
-  GPR_TIMER_BEGIN("cc_start_transport_stream_op", 0);
+  GPR_TIMER_BEGIN("cc_start_transport_stream_op_batch", 0);
   if (call == CANCELLED_CALL) {
-    grpc_transport_stream_op_finish_with_failure(
+    grpc_transport_stream_op_batch_finish_with_failure(
         exec_ctx, op, GRPC_ERROR_REF(calld->cancel_error));
-    GPR_TIMER_END("cc_start_transport_stream_op", 0);
+    GPR_TIMER_END("cc_start_transport_stream_op_batch", 0);
     /* early out */
     return;
   }
   if (call != NULL) {
     grpc_subchannel_call_process_op(exec_ctx, call, op);
-    GPR_TIMER_END("cc_start_transport_stream_op", 0);
+    GPR_TIMER_END("cc_start_transport_stream_op_batch", 0);
     /* early out */
     return;
   }
   /* we failed; lock and figure out what to do */
-  GRPC_CALL_STACK_REF(calld->owning_call, "start_transport_stream_op");
-  op->handler_private.args[0] = elem;
+  GRPC_CALL_STACK_REF(calld->owning_call, "start_transport_stream_op_batch");
+  op->handler_private.extra_arg = elem;
   grpc_closure_sched(
       exec_ctx,
       grpc_closure_init(&op->handler_private.closure,
-                        start_transport_stream_op_locked, op,
+                        start_transport_stream_op_batch_locked, op,
                         grpc_combiner_scheduler(chand->combiner, false)),
       GRPC_ERROR_NONE);
-  GPR_TIMER_END("cc_start_transport_stream_op", 0);
+  GPR_TIMER_END("cc_start_transport_stream_op_batch", 0);
 }
 
 /* Constructor for call_data */
@@ -1296,7 +1313,7 @@ static void cc_set_pollset_or_pollset_set(grpc_exec_ctx *exec_ctx,
  */
 
 const grpc_channel_filter grpc_client_channel_filter = {
-    cc_start_transport_stream_op,
+    cc_start_transport_stream_op_batch,
     cc_start_transport_op,
     sizeof(call_data),
     cc_init_call_elem,
diff --git a/src/core/ext/client_channel/client_channel.h b/src/core/ext/filters/client_channel/client_channel.h
index 5e6e64e58b..8d2490ea55 100644
--- a/src/core/ext/client_channel/client_channel.h
+++ b/src/core/ext/filters/client_channel/client_channel.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H
 
-#include "src/core/ext/client_channel/client_channel_factory.h"
-#include "src/core/ext/client_channel/resolver.h"
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
+#include "src/core/ext/filters/client_channel/resolver.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 // Channel arg key for server URI string.
@@ -61,4 +61,4 @@ void grpc_client_channel_watch_connectivity_state(
 grpc_subchannel_call *grpc_client_channel_get_subchannel_call(
     grpc_call_element *elem);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_H */
diff --git a/src/core/ext/client_channel/client_channel_factory.c b/src/core/ext/filters/client_channel/client_channel_factory.c
index d2707a1556..44e83b54b5 100644
--- a/src/core/ext/client_channel/client_channel_factory.c
+++ b/src/core/ext/filters/client_channel/client_channel_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/client_channel_factory.h"
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
 
 void grpc_client_channel_factory_ref(grpc_client_channel_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/ext/client_channel/client_channel_factory.h b/src/core/ext/filters/client_channel/client_channel_factory.h
index bf2764b537..2355588f18 100644
--- a/src/core/ext/client_channel/client_channel_factory.h
+++ b/src/core/ext/filters/client_channel/client_channel_factory.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H
 
 #include <grpc/impl/codegen/grpc_types.h>
 
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 // Channel arg key for client channel factory.
@@ -89,4 +89,4 @@ grpc_channel *grpc_client_channel_factory_create_channel(
 grpc_arg grpc_client_channel_factory_create_channel_arg(
     grpc_client_channel_factory *factory);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CLIENT_CHANNEL_FACTORY_H */
diff --git a/src/core/ext/client_channel/client_channel_plugin.c b/src/core/ext/filters/client_channel/client_channel_plugin.c
index f51277d0b2..a68c01c222 100644
--- a/src/core/ext/client_channel/client_channel_plugin.c
+++ b/src/core/ext/filters/client_channel/client_channel_plugin.c
@@ -31,20 +31,22 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
 #include <limits.h>
 #include <stdbool.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
-#include "src/core/ext/client_channel/http_proxy.h"
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/proxy_mapper_registry.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
-#include "src/core/ext/client_channel/retry_throttle.h"
-#include "src/core/ext/client_channel/subchannel_index.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/http_proxy.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/retry_throttle.h"
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/lib/surface/channel_init.h"
 
 static bool append_filter(grpc_exec_ctx *exec_ctx,
diff --git a/src/core/ext/client_channel/connector.c b/src/core/ext/filters/client_channel/connector.c
index 7a720fd1bd..51c1d7ece7 100644
--- a/src/core/ext/client_channel/connector.c
+++ b/src/core/ext/filters/client_channel/connector.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/connector.h"
+#include "src/core/ext/filters/client_channel/connector.h"
 
 grpc_connector* grpc_connector_ref(grpc_connector* connector) {
   connector->vtable->ref(connector);
diff --git a/src/core/ext/client_channel/connector.h b/src/core/ext/filters/client_channel/connector.h
index 94b5fb5c9e..23040c3e23 100644
--- a/src/core/ext/client_channel/connector.h
+++ b/src/core/ext/filters/client_channel/connector.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H
 
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/resolve_address.h"
@@ -85,4 +85,4 @@ void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
 void grpc_connector_shutdown(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
                              grpc_error *why);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_CONNECTOR_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_CONNECTOR_H */
diff --git a/src/core/ext/client_channel/http_connect_handshaker.c b/src/core/ext/filters/client_channel/http_connect_handshaker.c
index 778d76c39f..c09a863d00 100644
--- a/src/core/ext/client_channel/http_connect_handshaker.c
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
 
 #include <string.h>
 
@@ -40,9 +40,9 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker_registry.h"
 #include "src/core/lib/http/format_request.h"
diff --git a/src/core/ext/client_channel/http_connect_handshaker.h b/src/core/ext/filters/client_channel/http_connect_handshaker.h
index 3059d551e3..6d7c204d71 100644
--- a/src/core/ext/client_channel/http_connect_handshaker.h
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H
 
 /// Channel arg indicating the server in HTTP CONNECT request (string).
 /// The presence of this arg triggers the use of HTTP CONNECT.
@@ -46,4 +46,4 @@
 /// Registers handshaker factory.
 void grpc_http_connect_register_handshaker_factory();
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_CONNECT_HANDSHAKER_H */
diff --git a/src/core/ext/client_channel/http_proxy.c b/src/core/ext/filters/client_channel/http_proxy.c
index e280cef101..f8a2d06b8a 100644
--- a/src/core/ext/client_channel/http_proxy.c
+++ b/src/core/ext/filters/client_channel/http_proxy.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/http_proxy.h"
+#include "src/core/ext/filters/client_channel/http_proxy.h"
 
 #include <stdbool.h>
 #include <string.h>
@@ -40,9 +40,9 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
-#include "src/core/ext/client_channel/proxy_mapper_registry.h"
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/support/env.h"
 
diff --git a/src/core/ext/client_channel/http_proxy.h b/src/core/ext/filters/client_channel/http_proxy.h
index c8882b1ef1..f0df74bbda 100644
--- a/src/core/ext/client_channel/http_proxy.h
+++ b/src/core/ext/filters/client_channel/http_proxy.h
@@ -31,9 +31,9 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_PROXY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_PROXY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H
 
 void grpc_register_http_proxy_mapper();
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_HTTP_PROXY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_HTTP_PROXY_H */
diff --git a/src/core/ext/client_channel/lb_policy.c b/src/core/ext/filters/client_channel/lb_policy.c
index aba51add53..2d31499d13 100644
--- a/src/core/ext/client_channel/lb_policy.c
+++ b/src/core/ext/filters/client_channel/lb_policy.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/lb_policy.h"
+#include "src/core/ext/filters/client_channel/lb_policy.h"
 #include "src/core/lib/iomgr/combiner.h"
 
 #define WEAK_REF_BITS 16
diff --git a/src/core/ext/client_channel/lb_policy.h b/src/core/ext/filters/client_channel/lb_policy.h
index 3405709c2c..25427666ae 100644
--- a/src/core/ext/client_channel/lb_policy.h
+++ b/src/core/ext/filters/client_channel/lb_policy.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_H
 
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
@@ -206,4 +206,4 @@ grpc_connectivity_state grpc_lb_policy_check_connectivity_locked(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
     grpc_error **connectivity_error);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_H */
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
index 601b0e643b..ff8d319309 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.c
@@ -106,14 +106,14 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/client_channel_factory.h"
-#include "src/core/ext/client_channel/lb_policy_factory.h"
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/parse_address.h"
-#include "src/core/ext/lb_policy/grpclb/grpclb.h"
-#include "src/core/ext/lb_policy/grpclb/grpclb_channel.h"
-#include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr.h"
@@ -847,7 +847,9 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * this is the right LB policy to use. */
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
-  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
+    return NULL;
+  }
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_grpclb_addrs = 0;
   for (size_t i = 0; i < addresses->num_addresses; ++i) {
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
index ff23f3a545..b069fae2f8 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.h
@@ -31,14 +31,14 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_H
-#define GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 
 /** Returns a load balancing factory for the glb policy, which tries to connect
  * to a load balancing server to decide the next successfully connected
  * subchannel to pick. */
 grpc_lb_policy_factory *grpc_glb_lb_factory_create();
 
-#endif /* GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_H */
diff --git a/src/core/ext/lb_policy/grpclb/grpclb_channel.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.c
index 1b8bbab1b6..d6201f2387 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb_channel.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.c
@@ -34,8 +34,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/lb_policy/grpclb/grpclb_channel.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/support/string.h"
diff --git a/src/core/ext/lb_policy/grpclb/grpclb_channel.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h
index f66082d78e..9730c971d9 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb_channel.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H
-#define GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 #include "src/core/lib/slice/slice_hash_table.h"
 
 /** Create the channel used for communicating with an LB service.
@@ -53,4 +53,5 @@ grpc_channel_args *get_lb_channel_args(grpc_exec_ctx *exec_ctx,
                                        grpc_slice_hash_table *targets_info,
                                        const grpc_channel_args *args);
 
-#endif /* GRPC_CORE_EXT_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H \
+          */
diff --git a/src/core/ext/lb_policy/grpclb/grpclb_channel_secure.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.c
index 2fee5f1b8e..a145cba63c 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb_channel_secure.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.c
@@ -34,8 +34,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/lb_policy/grpclb/grpclb_channel.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/security/credentials/credentials.h"
diff --git a/src/core/ext/lb_policy/grpclb/load_balancer_api.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
index 3c4604c402..10af252531 100644
--- a/src/core/ext/lb_policy/grpclb/load_balancer_api.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/lb_policy/grpclb/load_balancer_api.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h"
 #include "third_party/nanopb/pb_decode.h"
 #include "third_party/nanopb/pb_encode.h"
 
diff --git a/src/core/ext/lb_policy/grpclb/load_balancer_api.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
index b4c967e426..d014b8800c 100644
--- a/src/core/ext/lb_policy/grpclb/load_balancer_api.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/load_balancer_api.h
@@ -31,13 +31,13 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H
-#define GRPC_CORE_EXT_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H
 
 #include <grpc/slice_buffer.h>
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
-#include "src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -101,4 +101,5 @@ void grpc_grpclb_initial_response_destroy(
 }
 #endif
 
-#endif /* GRPC_CORE_EXT_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_LOAD_BALANCER_API_H \
+          */
diff --git a/src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c b/src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c
index e352e0396f..e9adf98711 100644
--- a/src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.c
@@ -1,7 +1,7 @@
 /* Automatically generated nanopb constant definitions */
 /* Generated by nanopb-0.3.7-dev */
 
-#include "src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h"
+#include "src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h"
 
 /* @@protoc_insertion_point(includes) */
 #if PB_PROTO_HEADER_VERSION != 30
diff --git a/src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h
index 725aa7e386..725aa7e386 100644
--- a/src/core/ext/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/proto/grpc/lb/v1/load_balancer.pb.h
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
index fc65dfdcb9..2b77cd39b8 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
@@ -35,8 +35,8 @@
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
@@ -402,7 +402,9 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
    * addresses, since we don't know how to handle them. */
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
-  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
+    return NULL;
+  }
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
   for (size_t i = 0; i < addresses->num_addresses; i++) {
diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
index a62082a2ff..ff41e61b3e 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.c
@@ -63,8 +63,8 @@
 
 #include <grpc/support/alloc.h>
 
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -691,7 +691,9 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
    * addresses, since we don't know how to handle them. */
   const grpc_arg *arg =
       grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
-  GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+  if (arg == NULL || arg->type != GRPC_ARG_POINTER) {
+    return NULL;
+  }
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
   for (size_t i = 0; i < addresses->num_addresses; i++) {
diff --git a/src/core/ext/client_channel/lb_policy_factory.c b/src/core/ext/filters/client_channel/lb_policy_factory.c
index 7af9bb0411..e2af216b89 100644
--- a/src/core/ext/client_channel/lb_policy_factory.c
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.c
@@ -36,7 +36,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 
 grpc_lb_addresses* grpc_lb_addresses_create(
     size_t num_addresses, const grpc_lb_user_data_vtable* user_data_vtable) {
diff --git a/src/core/ext/client_channel/lb_policy_factory.h b/src/core/ext/filters/client_channel/lb_policy_factory.h
index 27c12c0d73..81ab12ec8f 100644
--- a/src/core/ext/client_channel/lb_policy_factory.h
+++ b/src/core/ext/filters/client_channel/lb_policy_factory.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H
 
-#include "src/core/ext/client_channel/client_channel_factory.h"
-#include "src/core/ext/client_channel/lb_policy.h"
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy.h"
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/resolve_address.h"
@@ -131,4 +131,4 @@ grpc_lb_policy *grpc_lb_policy_factory_create_lb_policy(
     grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory,
     grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_FACTORY_H */
diff --git a/src/core/ext/client_channel/lb_policy_registry.c b/src/core/ext/filters/client_channel/lb_policy_registry.c
index 90c149d947..1376673bca 100644
--- a/src/core/ext/client_channel/lb_policy_registry.c
+++ b/src/core/ext/filters/client_channel/lb_policy_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_channel/lb_policy_registry.h b/src/core/ext/filters/client_channel/lb_policy_registry.h
index 21c468e021..dfdec1347f 100644
--- a/src/core/ext/client_channel/lb_policy_registry.h
+++ b/src/core/ext/filters/client_channel/lb_policy_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 
 /** Initialize the registry and set \a default_factory as the factory to be
@@ -52,4 +52,4 @@ void grpc_register_lb_policy(grpc_lb_policy_factory *factory);
 grpc_lb_policy *grpc_lb_policy_create(grpc_exec_ctx *exec_ctx, const char *name,
                                       grpc_lb_policy_args *args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_REGISTRY_H */
diff --git a/src/core/ext/client_channel/parse_address.c b/src/core/ext/filters/client_channel/parse_address.c
index cd1b2cd80c..0c97062075 100644
--- a/src/core/ext/client_channel/parse_address.c
+++ b/src/core/ext/filters/client_channel/parse_address.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/parse_address.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 
 #include <stdio.h>
diff --git a/src/core/ext/client_channel/parse_address.h b/src/core/ext/filters/client_channel/parse_address.h
index bf99c5298a..c8d77baa00 100644
--- a/src/core/ext/client_channel/parse_address.h
+++ b/src/core/ext/filters/client_channel/parse_address.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H
 
 #include <stddef.h>
 
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
 /** Populate \a addr and \a len from \a uri, whose path is expected to contain a
@@ -51,4 +51,4 @@ int parse_ipv4(grpc_uri *uri, grpc_resolved_address *resolved_addr);
  * host:port pair. Returns true upon success. */
 int parse_ipv6(grpc_uri *uri, grpc_resolved_address *resolved_addr);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_PARSE_ADDRESS_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PARSE_ADDRESS_H */
diff --git a/src/core/ext/client_channel/proxy_mapper.c b/src/core/ext/filters/client_channel/proxy_mapper.c
index f92afe847b..6dddd3c6da 100644
--- a/src/core/ext/client_channel/proxy_mapper.c
+++ b/src/core/ext/filters/client_channel/proxy_mapper.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/proxy_mapper.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper.h"
 
 void grpc_proxy_mapper_init(const grpc_proxy_mapper_vtable* vtable,
                             grpc_proxy_mapper* mapper) {
diff --git a/src/core/ext/client_channel/proxy_mapper.h b/src/core/ext/filters/client_channel/proxy_mapper.h
index 6e4607fe4d..d0c47d3090 100644
--- a/src/core/ext/client_channel/proxy_mapper.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H
 
 #include <stdbool.h>
 
@@ -86,4 +86,4 @@ bool grpc_proxy_mapper_map_address(grpc_exec_ctx* exec_ctx,
 
 void grpc_proxy_mapper_destroy(grpc_proxy_mapper* mapper);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_H */
diff --git a/src/core/ext/client_channel/proxy_mapper_registry.c b/src/core/ext/filters/client_channel/proxy_mapper_registry.c
index 0935ddbdbd..7a39289a84 100644
--- a/src/core/ext/client_channel/proxy_mapper_registry.c
+++ b/src/core/ext/filters/client_channel/proxy_mapper_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_channel/proxy_mapper_registry.h b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
index 742b57a2d4..8b5686d664 100644
--- a/src/core/ext/client_channel/proxy_mapper_registry.h
+++ b/src/core/ext/filters/client_channel/proxy_mapper_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H
 
-#include "src/core/ext/client_channel/proxy_mapper.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper.h"
 
 void grpc_proxy_mapper_registry_init();
 void grpc_proxy_mapper_registry_shutdown();
@@ -56,4 +56,4 @@ bool grpc_proxy_mappers_map_address(grpc_exec_ctx* exec_ctx,
                                     grpc_resolved_address** new_address,
                                     grpc_channel_args** new_args);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_PROXY_MAPPER_REGISTRY_H */
diff --git a/src/core/ext/client_channel/resolver.c b/src/core/ext/filters/client_channel/resolver.c
index b1a1faa6c9..cafa2837f3 100644
--- a/src/core/ext/client_channel/resolver.c
+++ b/src/core/ext/filters/client_channel/resolver.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/resolver.h"
+#include "src/core/ext/filters/client_channel/resolver.h"
 #include "src/core/lib/iomgr/combiner.h"
 
 void grpc_resolver_init(grpc_resolver *resolver,
diff --git a/src/core/ext/client_channel/resolver.h b/src/core/ext/filters/client_channel/resolver.h
index bbba424ca5..55f9124b3a 100644
--- a/src/core/ext/client_channel/resolver.h
+++ b/src/core/ext/filters/client_channel/resolver.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_H
 
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/lib/iomgr/iomgr.h"
 
 typedef struct grpc_resolver grpc_resolver;
@@ -98,4 +98,4 @@ void grpc_resolver_next_locked(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
                                grpc_channel_args **result,
                                grpc_closure *on_complete);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_H */
diff --git a/src/core/ext/resolver/README.md b/src/core/ext/filters/client_channel/resolver/README.md
index b0e234e96a..b0e234e96a 100644
--- a/src/core/ext/resolver/README.md
+++ b/src/core/ext/filters/client_channel/resolver/README.md
diff --git a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
index f27da231f5..ffaeeed324 100644
--- a/src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.c
@@ -40,10 +40,10 @@
 #include <grpc/support/host_port.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/resolve_address.h"
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
index 334feaa2ab..aa88940021 100644
--- a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
-#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H
 
 #include <ares.h>
 
@@ -62,4 +62,5 @@ grpc_error *grpc_ares_ev_driver_create(grpc_ares_ev_driver **ev_driver,
    of ARES_ECANCELLED. */
 void grpc_ares_ev_driver_destroy(grpc_ares_ev_driver *ev_driver);
 
-#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H \
+          */
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
index fab4f0c977..1e4f3eb5ab 100644
--- a/src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c
@@ -34,14 +34,14 @@
 #include "src/core/lib/iomgr/port.h"
 #if GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET)
 
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
index 3eee8e3513..09c46a66e0 100644
--- a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c
@@ -34,7 +34,7 @@
 #include <grpc/support/port_platform.h>
 #if GRPC_ARES == 1 && !defined(GRPC_UV)
 
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/iomgr/sockaddr.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
@@ -48,7 +48,7 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
-#include "src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
 #include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
diff --git a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
index ab00a26b36..3dd40ea268 100644
--- a/src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.h
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
-#define GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/iomgr.h"
@@ -60,4 +60,5 @@ grpc_error *grpc_ares_init(void);
    it has been called the same number of times as grpc_ares_init(). */
 void grpc_ares_cleanup(void);
 
-#endif /* GRPC_CORE_EXT_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_WRAPPER_H \
+          */
diff --git a/src/core/ext/resolver/dns/native/README.md b/src/core/ext/filters/client_channel/resolver/dns/native/README.md
index 695de47b9f..695de47b9f 100644
--- a/src/core/ext/resolver/dns/native/README.md
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/README.md
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.c
index 97cd0486a9..ebe6a07215 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.c
@@ -37,8 +37,8 @@
 #include <grpc/support/host_port.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/lb_policy_registry.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/lb_policy_registry.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/resolve_address.h"
diff --git a/src/core/ext/resolver/sockaddr/README.md b/src/core/ext/filters/client_channel/resolver/sockaddr/README.md
index e307ba88f5..e307ba88f5 100644
--- a/src/core/ext/resolver/sockaddr/README.md
+++ b/src/core/ext/filters/client_channel/resolver/sockaddr/README.md
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.c
index da5923d26f..54f020d691 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.c
@@ -41,9 +41,9 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/lb_policy_factory.h"
-#include "src/core/ext/client_channel/parse_address.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/lb_policy_factory.h"
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/resolve_address.h"
diff --git a/src/core/ext/client_channel/resolver_factory.c b/src/core/ext/filters/client_channel/resolver_factory.c
index 00bbb92dd0..07f9e4cf03 100644
--- a/src/core/ext/client_channel/resolver_factory.c
+++ b/src/core/ext/filters/client_channel/resolver_factory.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/resolver_factory.h"
+#include "src/core/ext/filters/client_channel/resolver_factory.h"
 
 void grpc_resolver_factory_ref(grpc_resolver_factory* factory) {
   factory->vtable->ref(factory);
diff --git a/src/core/ext/client_channel/resolver_factory.h b/src/core/ext/filters/client_channel/resolver_factory.h
index e3cd99ec5a..f2fcfc06fe 100644
--- a/src/core/ext/client_channel/resolver_factory.h
+++ b/src/core/ext/filters/client_channel/resolver_factory.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H
 
-#include "src/core/ext/client_channel/client_channel_factory.h"
-#include "src/core/ext/client_channel/resolver.h"
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/client_channel_factory.h"
+#include "src/core/ext/filters/client_channel/resolver.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
 typedef struct grpc_resolver_factory grpc_resolver_factory;
@@ -82,4 +82,4 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
 char *grpc_resolver_factory_get_default_authority(
     grpc_resolver_factory *factory, grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_FACTORY_H */
diff --git a/src/core/ext/client_channel/resolver_registry.c b/src/core/ext/filters/client_channel/resolver_registry.c
index 0f074a3386..fa997bd68f 100644
--- a/src/core/ext/client_channel/resolver_registry.c
+++ b/src/core/ext/filters/client_channel/resolver_registry.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_channel/resolver_registry.h b/src/core/ext/filters/client_channel/resolver_registry.h
index 1a3ebee25a..f2e9f9249c 100644
--- a/src/core/ext/client_channel/resolver_registry.h
+++ b/src/core/ext/filters/client_channel/resolver_registry.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H
 
-#include "src/core/ext/client_channel/resolver_factory.h"
+#include "src/core/ext/filters/client_channel/resolver_factory.h"
 #include "src/core/lib/iomgr/pollset_set.h"
 
 void grpc_resolver_registry_init();
@@ -81,4 +81,4 @@ char *grpc_get_default_authority(grpc_exec_ctx *exec_ctx, const char *target);
 char *grpc_resolver_factory_add_default_prefix_if_needed(
     grpc_exec_ctx *exec_ctx, const char *target);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */
diff --git a/src/core/ext/client_channel/retry_throttle.c b/src/core/ext/filters/client_channel/retry_throttle.c
index 8926c3d782..dd78a17844 100644
--- a/src/core/ext/client_channel/retry_throttle.c
+++ b/src/core/ext/filters/client_channel/retry_throttle.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/retry_throttle.h"
+#include "src/core/ext/filters/client_channel/retry_throttle.h"
 
 #include <limits.h>
 #include <string.h>
diff --git a/src/core/ext/client_channel/retry_throttle.h b/src/core/ext/filters/client_channel/retry_throttle.h
index f9971faf65..640865cf90 100644
--- a/src/core/ext/client_channel/retry_throttle.h
+++ b/src/core/ext/filters/client_channel/retry_throttle.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_RETRY_THROTTLE_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_RETRY_THROTTLE_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H
 
 #include <stdbool.h>
 
@@ -62,4 +62,4 @@ void grpc_retry_throttle_map_shutdown();
 grpc_server_retry_throttle_data* grpc_retry_throttle_map_get_data_for_server(
     const char* server_name, int max_milli_tokens, int milli_token_ratio);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RETRY_THROTTLE_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */
diff --git a/src/core/ext/client_channel/subchannel.c b/src/core/ext/filters/client_channel/subchannel.c
index 063c0badff..9a7a7a0ee5 100644
--- a/src/core/ext/client_channel/subchannel.c
+++ b/src/core/ext/filters/client_channel/subchannel.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 
 #include <limits.h>
 #include <string.h>
@@ -40,11 +40,11 @@
 #include <grpc/support/avl.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/parse_address.h"
-#include "src/core/ext/client_channel/proxy_mapper_registry.h"
-#include "src/core/ext/client_channel/subchannel_index.h"
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/parse_address.h"
+#include "src/core/ext/filters/client_channel/proxy_mapper_registry.h"
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
@@ -360,7 +360,6 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
     for (size_t i = 0; i < c->args->num_args; i++) {
       if (0 == strcmp(c->args->args[i].key,
                       "grpc.testing.fixed_reconnect_backoff_ms")) {
-        GPR_ASSERT(c->args->args[i].type == GRPC_ARG_INTEGER);
         fixed_reconnect_backoff = true;
         initial_backoff_ms = min_backoff_ms = max_backoff_ms =
             grpc_channel_arg_get_integer(
@@ -749,11 +748,11 @@ char *grpc_subchannel_call_get_peer(grpc_exec_ctx *exec_ctx,
 
 void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
                                      grpc_subchannel_call *call,
-                                     grpc_transport_stream_op *op) {
+                                     grpc_transport_stream_op_batch *op) {
   GPR_TIMER_BEGIN("grpc_subchannel_call_process_op", 0);
   grpc_call_stack *call_stack = SUBCHANNEL_CALL_TO_CALL_STACK(call);
   grpc_call_element *top_elem = grpc_call_stack_element(call_stack, 0);
-  top_elem->filter->start_transport_stream_op(exec_ctx, top_elem, op);
+  top_elem->filter->start_transport_stream_op_batch(exec_ctx, top_elem, op);
   GPR_TIMER_END("grpc_subchannel_call_process_op", 0);
 }
 
@@ -770,7 +769,7 @@ grpc_error *grpc_connected_subchannel_create_call(
   *call = gpr_arena_alloc(
       args->arena, sizeof(grpc_subchannel_call) + chanstk->call_stack_size);
   grpc_call_stack *callstk = SUBCHANNEL_CALL_TO_CALL_STACK(*call);
-  (*call)->connection = con;  // Ref is added below.
+  (*call)->connection = GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
   const grpc_call_element_args call_args = {.call_stack = callstk,
                                             .server_transport_data = NULL,
                                             .context = NULL,
@@ -783,11 +782,8 @@ grpc_error *grpc_connected_subchannel_create_call(
   if (error != GRPC_ERROR_NONE) {
     const char *error_string = grpc_error_string(error);
     gpr_log(GPR_ERROR, "error: %s", error_string);
-
-    gpr_free(*call);
     return error;
   }
-  GRPC_CONNECTED_SUBCHANNEL_REF(con, "subchannel_call");
   grpc_call_stack_set_pollset_or_pollset_set(exec_ctx, callstk, args->pollent);
   return GRPC_ERROR_NONE;
 }
diff --git a/src/core/ext/client_channel/subchannel.h b/src/core/ext/filters/client_channel/subchannel.h
index 3e64a2507c..6473de49b0 100644
--- a/src/core/ext/client_channel/subchannel.h
+++ b/src/core/ext/filters/client_channel/subchannel.h
@@ -31,10 +31,10 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_H
 
-#include "src/core/ext/client_channel/connector.h"
+#include "src/core/ext/filters/client_channel/connector.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/support/arena.h"
@@ -157,7 +157,7 @@ grpc_connected_subchannel *grpc_subchannel_get_connected_subchannel(
 /** continue processing a transport op */
 void grpc_subchannel_call_process_op(grpc_exec_ctx *exec_ctx,
                                      grpc_subchannel_call *subchannel_call,
-                                     grpc_transport_stream_op *op);
+                                     grpc_transport_stream_op_batch *op);
 
 /** continue querying for peer */
 char *grpc_subchannel_call_get_peer(grpc_exec_ctx *exec_ctx,
@@ -200,4 +200,4 @@ const char *grpc_get_subchannel_address_uri_arg(const grpc_channel_args *args);
 /// Caller is responsible for freeing the string.
 grpc_arg grpc_create_subchannel_address_arg(const grpc_resolved_address *addr);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_H */
diff --git a/src/core/ext/client_channel/subchannel_index.c b/src/core/ext/filters/client_channel/subchannel_index.c
index 11889300a2..f6ef4a845e 100644
--- a/src/core/ext/client_channel/subchannel_index.c
+++ b/src/core/ext/filters/client_channel/subchannel_index.c
@@ -31,7 +31,7 @@
 //
 //
 
-#include "src/core/ext/client_channel/subchannel_index.h"
+#include "src/core/ext/filters/client_channel/subchannel_index.h"
 
 #include <stdbool.h>
 #include <string.h>
diff --git a/src/core/ext/client_channel/subchannel_index.h b/src/core/ext/filters/client_channel/subchannel_index.h
index a67bd5e219..f673ade378 100644
--- a/src/core/ext/client_channel/subchannel_index.h
+++ b/src/core/ext/filters/client_channel/subchannel_index.h
@@ -31,11 +31,11 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H
 
-#include "src/core/ext/client_channel/connector.h"
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/connector.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 
 /** \file Provides an index of active subchannels so that they can be
     shared amongst channels */
@@ -74,4 +74,4 @@ void grpc_subchannel_index_init(void);
 /** Shutdown the subchannel index (global) */
 void grpc_subchannel_index_shutdown(void);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_SUBCHANNEL_INDEX_H */
diff --git a/src/core/ext/client_channel/uri_parser.c b/src/core/ext/filters/client_channel/uri_parser.c
index d385db0801..01b99911aa 100644
--- a/src/core/ext/client_channel/uri_parser.c
+++ b/src/core/ext/filters/client_channel/uri_parser.c
@@ -31,7 +31,7 @@
  *
  */
 
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 
 #include <string.h>
 
diff --git a/src/core/ext/client_channel/uri_parser.h b/src/core/ext/filters/client_channel/uri_parser.h
index efd4302c1c..2698d448d8 100644
--- a/src/core/ext/client_channel/uri_parser.h
+++ b/src/core/ext/filters/client_channel/uri_parser.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H
-#define GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H
+#ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H
+#define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H
 
 #include <stddef.h>
 #include "src/core/lib/iomgr/exec_ctx.h"
@@ -62,4 +62,4 @@ const char *grpc_uri_get_query_arg(const grpc_uri *uri, const char *key);
 /** destroy a uri */
 void grpc_uri_destroy(grpc_uri *uri);
 
-#endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_URI_PARSER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_URI_PARSER_H */
diff --git a/src/core/ext/load_reporting/load_reporting.c b/src/core/ext/filters/load_reporting/load_reporting.c
index 942aea4fd1..f4dac15a60 100644
--- a/src/core/ext/load_reporting/load_reporting.c
+++ b/src/core/ext/filters/load_reporting/load_reporting.c
@@ -31,6 +31,8 @@
  *
  */
 
+#include <grpc/support/port_platform.h>
+
 #include <limits.h>
 #include <string.h>
 
@@ -38,8 +40,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/sync.h>
 
-#include "src/core/ext/load_reporting/load_reporting.h"
-#include "src/core/ext/load_reporting/load_reporting_filter.h"
+#include "src/core/ext/filters/load_reporting/load_reporting.h"
+#include "src/core/ext/filters/load_reporting/load_reporting_filter.h"
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/call.h"
diff --git a/src/core/ext/load_reporting/load_reporting.h b/src/core/ext/filters/load_reporting/load_reporting.h
index 22859a599a..e05a9dcc71 100644
--- a/src/core/ext/load_reporting/load_reporting.h
+++ b/src/core/ext/filters/load_reporting/load_reporting.h
@@ -31,8 +31,8 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
-#define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H
+#ifndef GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_H
+#define GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_H
 
 #include <grpc/impl/codegen/grpc_types.h>
 
@@ -70,4 +70,4 @@ typedef struct grpc_load_reporting_call_data {
 /** Return a \a grpc_arg enabling load reporting */
 grpc_arg grpc_load_reporting_enable_arg();
 
-#endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_H */
+#endif /* GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_H */
diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/filters/load_reporting/load_reporting_filter.c
index ea57c85c3a..57b25d0651 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/filters/load_reporting/load_reporting_filter.c
@@ -39,8 +39,8 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 
-#include "src/core/ext/load_reporting/load_reporting.h"
-#include "src/core/ext/load_reporting/load_reporting_filter.h"
+#include "src/core/ext/filters/load_reporting/load_reporting.h"
+#include "src/core/ext/filters/load_reporting/load_reporting_filter.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
@@ -183,25 +183,28 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   */
 }
 
-static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
-                                         grpc_call_element *elem,
-                                         grpc_transport_stream_op *op) {
-  GPR_TIMER_BEGIN("lr_start_transport_stream_op", 0);
+static void lr_start_transport_stream_op_batch(
+    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+    grpc_transport_stream_op_batch *op) {
+  GPR_TIMER_BEGIN("lr_start_transport_stream_op_batch", 0);
   call_data *calld = elem->call_data;
 
   if (op->recv_initial_metadata) {
-    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->recv_initial_metadata =
+        op->payload->recv_initial_metadata.recv_initial_metadata;
     /* substitute our callback for the higher callback */
-    calld->ops_recv_initial_metadata_ready = op->recv_initial_metadata_ready;
-    op->recv_initial_metadata_ready = &calld->on_initial_md_ready;
+    calld->ops_recv_initial_metadata_ready =
+        op->payload->recv_initial_metadata.recv_initial_metadata_ready;
+    op->payload->recv_initial_metadata.recv_initial_metadata_ready =
+        &calld->on_initial_md_ready;
   }
   grpc_call_next_op(exec_ctx, elem, op);
 
-  GPR_TIMER_END("lr_start_transport_stream_op", 0);
+  GPR_TIMER_END("lr_start_transport_stream_op_batch", 0);
 }
 
 const grpc_channel_filter grpc_load_reporting_filter = {
-    lr_start_transport_stream_op,
+    lr_start_transport_stream_op_batch,
     grpc_channel_next_op,
     sizeof(call_data),
     init_call_elem,
diff --git a/src/core/ext/load_reporting/load_reporting_filter.h b/src/core/ext/filters/load_reporting/load_reporting_filter.h
index 160ed32af9..da884a1479 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.h
+++ b/src/core/ext/filters/load_reporting/load_reporting_filter.h
@@ -31,12 +31,12 @@
  *
  */
 
-#ifndef GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
-#define GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
+#ifndef GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
+#define GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_FILTER_H
 
-#include "src/core/ext/load_reporting/load_reporting.h"
+#include "src/core/ext/filters/load_reporting/load_reporting.h"
 #include "src/core/lib/channel/channel_stack.h"
 
 extern const grpc_channel_filter grpc_load_reporting_filter;
 
-#endif /* GRPC_CORE_EXT_LOAD_REPORTING_LOAD_REPORTING_FILTER_H */
+#endif /* GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_LOAD_REPORTING_FILTER_H */
diff --git a/src/core/ext/filters/max_age/max_age_filter.c b/src/core/ext/filters/max_age/max_age_filter.c
new file mode 100644
index 0000000000..b9fde36286
--- /dev/null
+++ b/src/core/ext/filters/max_age/max_age_filter.c
@@ -0,0 +1,439 @@
+/*
+ *
+ * Copyright 2017, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/ext/filters/max_age/max_age_filter.h"
+
+#include <limits.h>
+#include <string.h>
+
+#include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/channel/channel_stack_builder.h"
+#include "src/core/lib/iomgr/timer.h"
+#include "src/core/lib/surface/channel_init.h"
+#include "src/core/lib/transport/http2_errors.h"
+
+#define DEFAULT_MAX_CONNECTION_AGE_MS INT_MAX
+#define DEFAULT_MAX_CONNECTION_AGE_GRACE_MS INT_MAX
+#define DEFAULT_MAX_CONNECTION_IDLE_MS INT_MAX
+#define MAX_CONNECTION_AGE_JITTER 0.1
+
+typedef struct channel_data {
+  /* We take a reference to the channel stack for the timer callback */
+  grpc_channel_stack* channel_stack;
+  /* Guards access to max_age_timer, max_age_timer_pending, max_age_grace_timer
+     and max_age_grace_timer_pending */
+  gpr_mu max_age_timer_mu;
+  /* True if the max_age timer callback is currently pending */
+  bool max_age_timer_pending;
+  /* True if the max_age_grace timer callback is currently pending */
+  bool max_age_grace_timer_pending;
+  /* The timer for checking if the channel has reached its max age */
+  grpc_timer max_age_timer;
+  /* The timer for checking if the max-aged channel has uesed up the grace
+     period */
+  grpc_timer max_age_grace_timer;
+  /* The timer for checking if the channel's idle duration reaches
+     max_connection_idle */
+  grpc_timer max_idle_timer;
+  /* Allowed max time a channel may have no outstanding rpcs */
+  gpr_timespec max_connection_idle;
+  /* Allowed max time a channel may exist */
+  gpr_timespec max_connection_age;
+  /* Allowed grace period after the channel reaches its max age */
+  gpr_timespec max_connection_age_grace;
+  /* Closure to run when the channel's idle duration reaches max_connection_idle
+     and should be closed gracefully */
+  grpc_closure close_max_idle_channel;
+  /* Closure to run when the channel reaches its max age and should be closed
+     gracefully */
+  grpc_closure close_max_age_channel;
+  /* Closure to run the channel uses up its max age grace time and should be
+     closed forcibly */
+  grpc_closure force_close_max_age_channel;
+  /* Closure to run when the init fo channel stack is done and the max_idle
+     timer should be started */
+  grpc_closure start_max_idle_timer_after_init;
+  /* Closure to run when the init fo channel stack is done and the max_age timer
+     should be started */
+  grpc_closure start_max_age_timer_after_init;
+  /* Closure to run when the goaway op is finished and the max_age_timer */
+  grpc_closure start_max_age_grace_timer_after_goaway_op;
+  /* Closure to run when the channel connectivity state changes */
+  grpc_closure channel_connectivity_changed;
+  /* Records the current connectivity state */
+  grpc_connectivity_state connectivity_state;
+  /* Number of active calls */
+  gpr_atm call_count;
+} channel_data;
+
+/* Increase the nubmer of active calls. Before the increasement, if there are no
+   calls, the max_idle_timer should be cancelled. */
+static void increase_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
+  if (gpr_atm_full_fetch_add(&chand->call_count, 1) == 0) {
+    grpc_timer_cancel(exec_ctx, &chand->max_idle_timer);
+  }
+}
+
+/* Decrease the nubmer of active calls. After the decrement, if there are no
+   calls, the max_idle_timer should be started. */
+static void decrease_call_count(grpc_exec_ctx* exec_ctx, channel_data* chand) {
+  if (gpr_atm_full_fetch_add(&chand->call_count, -1) == 1) {
+    GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_idle_timer");
+    grpc_timer_init(
+        exec_ctx, &chand->max_idle_timer,
+        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_idle),
+        &chand->close_max_idle_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+  }
+}
+
+static void start_max_idle_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
+                                            grpc_error* error) {
+  channel_data* chand = arg;
+  /* Decrease call_count. If there are no active calls at this time,
+     max_idle_timer will start here. If the number of active calls is not 0,
+     max_idle_timer will start after all the active calls end. */
+  decrease_call_count(exec_ctx, chand);
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age start_max_idle_timer_after_init");
+}
+
+static void start_max_age_timer_after_init(grpc_exec_ctx* exec_ctx, void* arg,
+                                           grpc_error* error) {
+  channel_data* chand = arg;
+  gpr_mu_lock(&chand->max_age_timer_mu);
+  chand->max_age_timer_pending = true;
+  GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_timer");
+  grpc_timer_init(
+      exec_ctx, &chand->max_age_timer,
+      gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), chand->max_connection_age),
+      &chand->close_max_age_channel, gpr_now(GPR_CLOCK_MONOTONIC));
+  gpr_mu_unlock(&chand->max_age_timer_mu);
+  grpc_transport_op* op = grpc_make_transport_op(NULL);
+  op->on_connectivity_state_change = &chand->channel_connectivity_changed,
+  op->connectivity_state = &chand->connectivity_state;
+  grpc_channel_next_op(exec_ctx,
+                       grpc_channel_stack_element(chand->channel_stack, 0), op);
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age start_max_age_timer_after_init");
+}
+
+static void start_max_age_grace_timer_after_goaway_op(grpc_exec_ctx* exec_ctx,
+                                                      void* arg,
+                                                      grpc_error* error) {
+  channel_data* chand = arg;
+  gpr_mu_lock(&chand->max_age_timer_mu);
+  chand->max_age_grace_timer_pending = true;
+  GRPC_CHANNEL_STACK_REF(chand->channel_stack, "max_age max_age_grace_timer");
+  grpc_timer_init(exec_ctx, &chand->max_age_grace_timer,
+                  gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC),
+                               chand->max_connection_age_grace),
+                  &chand->force_close_max_age_channel,
+                  gpr_now(GPR_CLOCK_MONOTONIC));
+  gpr_mu_unlock(&chand->max_age_timer_mu);
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age start_max_age_grace_timer_after_goaway_op");
+}
+
+static void close_max_idle_channel(grpc_exec_ctx* exec_ctx, void* arg,
+                                   grpc_error* error) {
+  channel_data* chand = arg;
+  if (error == GRPC_ERROR_NONE) {
+    /* Prevent the max idle timer from being set again */
+    gpr_atm_no_barrier_fetch_add(&chand->call_count, 1);
+    grpc_transport_op* op = grpc_make_transport_op(NULL);
+    op->goaway_error =
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING("max_idle"),
+                           GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_NO_ERROR);
+    grpc_channel_element* elem =
+        grpc_channel_stack_element(chand->channel_stack, 0);
+    elem->filter->start_transport_op(exec_ctx, elem, op);
+  } else if (error != GRPC_ERROR_CANCELLED) {
+    GRPC_LOG_IF_ERROR("close_max_idle_channel", error);
+  }
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age max_idle_timer");
+}
+
+static void close_max_age_channel(grpc_exec_ctx* exec_ctx, void* arg,
+                                  grpc_error* error) {
+  channel_data* chand = arg;
+  gpr_mu_lock(&chand->max_age_timer_mu);
+  chand->max_age_timer_pending = false;
+  gpr_mu_unlock(&chand->max_age_timer_mu);
+  if (error == GRPC_ERROR_NONE) {
+    GRPC_CHANNEL_STACK_REF(chand->channel_stack,
+                           "max_age start_max_age_grace_timer_after_goaway_op");
+    grpc_transport_op* op = grpc_make_transport_op(
+        &chand->start_max_age_grace_timer_after_goaway_op);
+    op->goaway_error =
+        grpc_error_set_int(GRPC_ERROR_CREATE_FROM_STATIC_STRING("max_age"),
+                           GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_NO_ERROR);
+    grpc_channel_element* elem =
+        grpc_channel_stack_element(chand->channel_stack, 0);
+    elem->filter->start_transport_op(exec_ctx, elem, op);
+  } else if (error != GRPC_ERROR_CANCELLED) {
+    GRPC_LOG_IF_ERROR("close_max_age_channel", error);
+  }
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age max_age_timer");
+}
+
+static void force_close_max_age_channel(grpc_exec_ctx* exec_ctx, void* arg,
+                                        grpc_error* error) {
+  channel_data* chand = arg;
+  gpr_mu_lock(&chand->max_age_timer_mu);
+  chand->max_age_grace_timer_pending = false;
+  gpr_mu_unlock(&chand->max_age_timer_mu);
+  if (error == GRPC_ERROR_NONE) {
+    grpc_transport_op* op = grpc_make_transport_op(NULL);
+    op->disconnect_with_error =
+        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel reaches max age");
+    grpc_channel_element* elem =
+        grpc_channel_stack_element(chand->channel_stack, 0);
+    elem->filter->start_transport_op(exec_ctx, elem, op);
+  } else if (error != GRPC_ERROR_CANCELLED) {
+    GRPC_LOG_IF_ERROR("force_close_max_age_channel", error);
+  }
+  GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->channel_stack,
+                           "max_age max_age_grace_timer");
+}
+
+static void channel_connectivity_changed(grpc_exec_ctx* exec_ctx, void* arg,
+                                         grpc_error* error) {
+  channel_data* chand = arg;
+  if (chand->connectivity_state != GRPC_CHANNEL_SHUTDOWN) {
+    grpc_transport_op* op = grpc_make_transport_op(NULL);
+    op->on_connectivity_state_change = &chand->channel_connectivity_changed,
+    op->connectivity_state = &chand->connectivity_state;
+    grpc_channel_next_op(
+        exec_ctx, grpc_channel_stack_element(chand->channel_stack, 0), op);
+  } else {
+    gpr_mu_lock(&chand->max_age_timer_mu);
+    if (chand->max_age_timer_pending) {
+      grpc_timer_cancel(exec_ctx, &chand->max_age_timer);
+      chand->max_age_timer_pending = false;
+    }
+    if (chand->max_age_grace_timer_pending) {
+      grpc_timer_cancel(exec_ctx, &chand->max_age_grace_timer);
+      chand->max_age_grace_timer_pending = false;
+    }
+    gpr_mu_unlock(&chand->max_age_timer_mu);
+    /* If there are no active calls, this increasement will cancel
+       max_idle_timer, and prevent max_idle_timer from being started in the
+       future. */
+    increase_call_count(exec_ctx, chand);
+  }
+}
+
+/* A random jitter of +/-10% will be added to MAX_CONNECTION_AGE to spread out
+   connection storms. Note that the MAX_CONNECTION_AGE option without jitter
+   would not create connection storms by itself, but if there happened to be a
+   connection storm it could cause it to repeat at a fixed period. */
+static int add_random_max_connection_age_jitter(int value) {
+  /* generate a random number between 1 - MAX_CONNECTION_AGE_JITTER and
+     1 + MAX_CONNECTION_AGE_JITTER */
+  double multiplier = rand() * MAX_CONNECTION_AGE_JITTER * 2.0 / RAND_MAX +
+                      1.0 - MAX_CONNECTION_AGE_JITTER;
+  double result = multiplier * value;
+  /* INT_MAX - 0.5 converts the value to float, so that result will not be
+     cast to int implicitly before the comparison. */
+  return result > INT_MAX - 0.5 ? INT_MAX : (int)result;
+}
+
+/* Constructor for call_data. */
+static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
+                                  grpc_call_element* elem,
+                                  const grpc_call_element_args* args) {
+  channel_data* chand = elem->channel_data;
+  increase_call_count(exec_ctx, chand);
+  return GRPC_ERROR_NONE;
+}
+
+/* Destructor for call_data. */
+static void destroy_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                              const grpc_call_final_info* final_info,
+                              grpc_closure* ignored) {
+  channel_data* chand = elem->channel_data;
+  decrease_call_count(exec_ctx, chand);
+}
+
+/* Constructor for channel_data. */
+static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
+                                     grpc_channel_element* elem,
+                                     grpc_channel_element_args* args) {
+  channel_data* chand = elem->channel_data;
+  gpr_mu_init(&chand->max_age_timer_mu);
+  chand->max_age_timer_pending = false;
+  chand->max_age_grace_timer_pending = false;
+  chand->channel_stack = args->channel_stack;
+  chand->max_connection_age =
+      DEFAULT_MAX_CONNECTION_AGE_MS == INT_MAX
+          ? gpr_inf_future(GPR_TIMESPAN)
+          : gpr_time_from_millis(add_random_max_connection_age_jitter(
+                                     DEFAULT_MAX_CONNECTION_AGE_MS),
+                                 GPR_TIMESPAN);
+  chand->max_connection_age_grace =
+      DEFAULT_MAX_CONNECTION_AGE_GRACE_MS == INT_MAX
+          ? gpr_inf_future(GPR_TIMESPAN)
+          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_AGE_GRACE_MS,
+                                 GPR_TIMESPAN);
+  chand->max_connection_idle =
+      DEFAULT_MAX_CONNECTION_IDLE_MS == INT_MAX
+          ? gpr_inf_future(GPR_TIMESPAN)
+          : gpr_time_from_millis(DEFAULT_MAX_CONNECTION_IDLE_MS, GPR_TIMESPAN);
+  for (size_t i = 0; i < args->channel_args->num_args; ++i) {
+    if (0 == strcmp(args->channel_args->args[i].key,
+                    GRPC_ARG_MAX_CONNECTION_AGE_MS)) {
+      const int value = grpc_channel_arg_get_integer(
+          &args->channel_args->args[i],
+          (grpc_integer_options){DEFAULT_MAX_CONNECTION_AGE_MS, 1, INT_MAX});
+      chand->max_connection_age =
+          value == INT_MAX
+              ? gpr_inf_future(GPR_TIMESPAN)
+              : gpr_time_from_millis(
+                    add_random_max_connection_age_jitter(value), GPR_TIMESPAN);
+    } else if (0 == strcmp(args->channel_args->args[i].key,
+                           GRPC_ARG_MAX_CONNECTION_AGE_GRACE_MS)) {
+      const int value = grpc_channel_arg_get_integer(
+          &args->channel_args->args[i],
+          (grpc_integer_options){DEFAULT_MAX_CONNECTION_AGE_GRACE_MS, 0,
+                                 INT_MAX});
+      chand->max_connection_age_grace =
+          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
+                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+    } else if (0 == strcmp(args->channel_args->args[i].key,
+                           GRPC_ARG_MAX_CONNECTION_IDLE_MS)) {
+      const int value = grpc_channel_arg_get_integer(
+          &args->channel_args->args[i],
+          (grpc_integer_options){DEFAULT_MAX_CONNECTION_IDLE_MS, 1, INT_MAX});
+      chand->max_connection_idle =
+          value == INT_MAX ? gpr_inf_future(GPR_TIMESPAN)
+                           : gpr_time_from_millis(value, GPR_TIMESPAN);
+    }
+  }
+  grpc_closure_init(&chand->close_max_idle_channel, close_max_idle_channel,
+                    chand, grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->close_max_age_channel, close_max_age_channel, chand,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->force_close_max_age_channel,
+                    force_close_max_age_channel, chand,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->start_max_idle_timer_after_init,
+                    start_max_idle_timer_after_init, chand,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->start_max_age_timer_after_init,
+                    start_max_age_timer_after_init, chand,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->start_max_age_grace_timer_after_goaway_op,
+                    start_max_age_grace_timer_after_goaway_op, chand,
+                    grpc_schedule_on_exec_ctx);
+  grpc_closure_init(&chand->channel_connectivity_changed,
+                    channel_connectivity_changed, chand,
+                    grpc_schedule_on_exec_ctx);
+
+  if (gpr_time_cmp(chand->max_connection_age, gpr_inf_future(GPR_TIMESPAN)) !=
+      0) {
+    /* When the channel reaches its max age, we send down an op with
+       goaway_error set.  However, we can't send down any ops until after the
+       channel stack is fully initialized.  If we start the timer here, we have
+       no guarantee that the timer won't pop before channel stack initialization
+       is finished.  To avoid that problem, we create a closure to start the
+       timer, and we schedule that closure to be run after call stack
+       initialization is done. */
+    GRPC_CHANNEL_STACK_REF(chand->channel_stack,
+                           "max_age start_max_age_timer_after_init");
+    grpc_closure_sched(exec_ctx, &chand->start_max_age_timer_after_init,
+                       GRPC_ERROR_NONE);
+  }
+
+  /* Initialize the number of calls as 1, so that the max_idle_timer will not
+     start until start_max_idle_timer_after_init is invoked. */
+  gpr_atm_rel_store(&chand->call_count, 1);
+  if (gpr_time_cmp(chand->max_connection_idle, gpr_inf_future(GPR_TIMESPAN)) !=
+      0) {
+    GRPC_CHANNEL_STACK_REF(chand->channel_stack,
+                           "max_age start_max_idle_timer_after_init");
+    grpc_closure_sched(exec_ctx, &chand->start_max_idle_timer_after_init,
+                       GRPC_ERROR_NONE);
+  }
+  return GRPC_ERROR_NONE;
+}
+
+/* Destructor for channel_data. */
+static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
+                                 grpc_channel_element* elem) {}
+
+const grpc_channel_filter grpc_max_age_filter = {
+    grpc_call_next_op,
+    grpc_channel_next_op,
+    0, /* sizeof_call_data */
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    grpc_channel_next_get_info,
+    "max_age"};
+
+static bool maybe_add_max_age_filter(grpc_exec_ctx* exec_ctx,
+                                     grpc_channel_stack_builder* builder,
+                                     void* arg) {
+  const grpc_channel_args* channel_args =
+      grpc_channel_stack_builder_get_channel_arguments(builder);
+  const grpc_arg* a =
+      grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_AGE_MS);
+  bool enable = false;
+  if (a != NULL && a->type == GRPC_ARG_INTEGER && a->value.integer != INT_MAX) {
+    enable = true;
+  }
+  a = grpc_channel_args_find(channel_args, GRPC_ARG_MAX_CONNECTION_IDLE_MS);
+  if (a != NULL && a->type == GRPC_ARG_INTEGER && a->value.integer != INT_MAX) {
+    enable = true;
+  }
+  if (enable) {
+    return grpc_channel_stack_builder_prepend_filter(
+        builder, &grpc_max_age_filter, NULL, NULL);
+  } else {
+    return true;
+  }
+}
+
+void grpc_max_age_filter_init(void) {
+  grpc_channel_init_register_stage(GRPC_SERVER_CHANNEL,
+                                   GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+                                   maybe_add_max_age_filter, NULL);
+}
+
+void grpc_max_age_filter_shutdown(void) {}
diff --git a/src/core/ext/filters/max_age/max_age_filter.h b/src/core/ext/filters/max_age/max_age_filter.h
new file mode 100644
index 0000000000..ed2015297a
--- /dev/null
+++ b/src/core/ext/filters/max_age/max_age_filter.h
@@ -0,0 +1,39 @@
+//
+// Copyright 2017, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#ifndef GRPC_CORE_EXT_FILTERS_MAX_AGE_MAX_AGE_FILTER_H
+#define GRPC_CORE_EXT_FILTERS_MAX_AGE_MAX_AGE_FILTER_H
+
+#include "src/core/lib/channel/channel_stack.h"
+
+extern const grpc_channel_filter grpc_max_age_filter;
+
+#endif /* GRPC_CORE_EXT_FILTERS_MAX_AGE_MAX_AGE_FILTER_H */
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.c b/src/core/ext/transport/chttp2/client/chttp2_connector.c
index 2b226c1bf7..e645eda7e3 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.c
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.c
@@ -41,9 +41,9 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/connector.h"
-#include "src/core/ext/client_channel/http_connect_handshaker.h"
-#include "src/core/ext/client_channel/subchannel.h"
+#include "src/core/ext/filters/client_channel/connector.h"
+#include "src/core/ext/filters/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/filters/client_channel/subchannel.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.h b/src/core/ext/transport/chttp2/client/chttp2_connector.h
index f5d1025432..d55f6ed669 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.h
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.h
@@ -34,7 +34,7 @@
 #ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H
 #define GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H
 
-#include "src/core/ext/client_channel/connector.h"
+#include "src/core/ext/filters/client_channel/connector.h"
 
 grpc_connector* grpc_chttp2_connector_create();
 
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
index 067ac35a5a..9c8505ddfa 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -38,8 +38,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
 #include "src/core/ext/transport/chttp2/client/chttp2_connector.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/api_trace.h"
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
index f0c241d68e..119adfade1 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
@@ -38,9 +38,9 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_channel/client_channel.h"
-#include "src/core/ext/client_channel/resolver_registry.h"
-#include "src/core/ext/client_channel/uri_parser.h"
+#include "src/core/ext/filters/client_channel/client_channel.h"
+#include "src/core/ext/filters/client_channel/resolver_registry.h"
+#include "src/core/ext/filters/client_channel/uri_parser.h"
 #include "src/core/ext/transport/chttp2/client/chttp2_connector.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
index f46e849932..6ab176e8ad 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2_posix.c
@@ -57,12 +57,9 @@ void grpc_server_add_insecure_channel_from_fd(grpc_server *server,
   char *name;
   gpr_asprintf(&name, "fd:%d", fd);
 
-  grpc_resource_quota *resource_quota = grpc_resource_quota_from_channel_args(
-      grpc_server_get_channel_args(server));
   grpc_endpoint *server_endpoint =
-      grpc_tcp_create(grpc_fd_create(fd, name), resource_quota,
-                      GRPC_TCP_DEFAULT_READ_SLICE_SIZE, name);
-  grpc_resource_quota_unref_internal(&exec_ctx, resource_quota);
+      grpc_tcp_create(&exec_ctx, grpc_fd_create(fd, name),
+                      grpc_server_get_channel_args(server), name);
 
   gpr_free(name);
 
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 73f9454f7a..e2816b0e04 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -69,13 +69,21 @@
 #define MAX_WRITE_BUFFER_SIZE (64 * 1024 * 1024)
 #define DEFAULT_MAX_HEADER_LIST_SIZE (16 * 1024)
 
-#define DEFAULT_CLIENT_KEEPALIVE_TIME_S INT_MAX
-#define DEFAULT_CLIENT_KEEPALIVE_TIMEOUT_S 20
+#define DEFAULT_CLIENT_KEEPALIVE_TIME_MS INT_MAX
+#define DEFAULT_CLIENT_KEEPALIVE_TIMEOUT_MS 20000 /* 20 seconds */
+#define DEFAULT_SERVER_KEEPALIVE_TIME_MS 7200000  /* 2 hours */
+#define DEFAULT_SERVER_KEEPALIVE_TIMEOUT_MS 20000 /* 20 seconds */
 #define DEFAULT_KEEPALIVE_PERMIT_WITHOUT_CALLS false
-
-static int g_default_client_keepalive_time_s = DEFAULT_CLIENT_KEEPALIVE_TIME_S;
-static int g_default_client_keepalive_timeout_s =
-    DEFAULT_CLIENT_KEEPALIVE_TIMEOUT_S;
+#define KEEPALIVE_TIME_BACKOFF_MULTIPLIER 2
+
+static int g_default_client_keepalive_time_ms =
+    DEFAULT_CLIENT_KEEPALIVE_TIME_MS;
+static int g_default_client_keepalive_timeout_ms =
+    DEFAULT_CLIENT_KEEPALIVE_TIMEOUT_MS;
+static int g_default_server_keepalive_time_ms =
+    DEFAULT_SERVER_KEEPALIVE_TIME_MS;
+static int g_default_server_keepalive_timeout_ms =
+    DEFAULT_SERVER_KEEPALIVE_TIMEOUT_MS;
 static bool g_default_keepalive_permit_without_calls =
     DEFAULT_KEEPALIVE_PERMIT_WITHOUT_CALLS;
 
@@ -153,6 +161,8 @@ static void retry_initiate_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
 
 #define DEFAULT_MIN_TIME_BETWEEN_PINGS_MS 0
 #define DEFAULT_MAX_PINGS_BETWEEN_DATA 3
+#define DEFAULT_MAX_PING_STRIKES 2
+#define DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS 300000 /* 5 minutes */
 
 /** keepalive-relevant functions */
 static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
@@ -351,19 +361,35 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
       .max_pings_without_data = DEFAULT_MAX_PINGS_BETWEEN_DATA,
       .min_time_between_pings =
           gpr_time_from_millis(DEFAULT_MIN_TIME_BETWEEN_PINGS_MS, GPR_TIMESPAN),
+      .max_ping_strikes = DEFAULT_MAX_PING_STRIKES,
+      .min_ping_interval_without_data = gpr_time_from_millis(
+          DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS, GPR_TIMESPAN),
   };
 
-  /* client-side keepalive setting */
-  t->keepalive_time =
-      g_default_client_keepalive_time_s == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_seconds(g_default_client_keepalive_time_s,
-                                  GPR_TIMESPAN);
-  t->keepalive_timeout =
-      g_default_client_keepalive_timeout_s == INT_MAX
-          ? gpr_inf_future(GPR_TIMESPAN)
-          : gpr_time_from_seconds(g_default_client_keepalive_timeout_s,
-                                  GPR_TIMESPAN);
+  /* Keepalive setting */
+  if (t->is_client) {
+    t->keepalive_time =
+        g_default_client_keepalive_time_ms == INT_MAX
+            ? gpr_inf_future(GPR_TIMESPAN)
+            : gpr_time_from_millis(g_default_client_keepalive_time_ms,
+                                   GPR_TIMESPAN);
+    t->keepalive_timeout =
+        g_default_client_keepalive_timeout_ms == INT_MAX
+            ? gpr_inf_future(GPR_TIMESPAN)
+            : gpr_time_from_millis(g_default_client_keepalive_timeout_ms,
+                                   GPR_TIMESPAN);
+  } else {
+    t->keepalive_time =
+        g_default_server_keepalive_time_ms == INT_MAX
+            ? gpr_inf_future(GPR_TIMESPAN)
+            : gpr_time_from_millis(g_default_server_keepalive_time_ms,
+                                   GPR_TIMESPAN);
+    t->keepalive_timeout =
+        g_default_server_keepalive_timeout_ms == INT_MAX
+            ? gpr_inf_future(GPR_TIMESPAN)
+            : gpr_time_from_millis(g_default_server_keepalive_timeout_ms,
+                                   GPR_TIMESPAN);
+  }
   t->keepalive_permit_without_calls = g_default_keepalive_permit_without_calls;
 
   if (channel_args) {
@@ -397,6 +423,11 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
             &channel_args->args[i],
             (grpc_integer_options){DEFAULT_MAX_PINGS_BETWEEN_DATA, 0, INT_MAX});
       } else if (0 == strcmp(channel_args->args[i].key,
+                             GRPC_ARG_HTTP2_MAX_PING_STRIKES)) {
+        t->ping_policy.max_ping_strikes = grpc_channel_arg_get_integer(
+            &channel_args->args[i],
+            (grpc_integer_options){DEFAULT_MAX_PING_STRIKES, 0, INT_MAX});
+      } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_MIN_TIME_BETWEEN_PINGS_MS)) {
         t->ping_policy.min_time_between_pings = gpr_time_from_millis(
             grpc_channel_arg_get_integer(
@@ -404,6 +435,15 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                 (grpc_integer_options){DEFAULT_MIN_TIME_BETWEEN_PINGS_MS, 0,
                                        INT_MAX}),
             GPR_TIMESPAN);
+      } else if (0 ==
+                 strcmp(channel_args->args[i].key,
+                        GRPC_ARG_HTTP2_MIN_PING_INTERVAL_WITHOUT_DATA_MS)) {
+        t->ping_policy.min_ping_interval_without_data = gpr_time_from_millis(
+            grpc_channel_arg_get_integer(
+                &channel_args->args[i],
+                (grpc_integer_options){
+                    DEFAULT_MIN_PING_INTERVAL_WITHOUT_DATA_MS, 0, INT_MAX}),
+            GPR_TIMESPAN);
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_WRITE_BUFFER_SIZE)) {
         t->write_buffer_size = (uint32_t)grpc_channel_arg_get_integer(
@@ -414,23 +454,27 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
         t->enable_bdp_probe = grpc_channel_arg_get_integer(
             &channel_args->args[i], (grpc_integer_options){1, 0, 1});
       } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_CLIENT_KEEPALIVE_TIME_S)) {
+                             GRPC_ARG_KEEPALIVE_TIME_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){g_default_client_keepalive_time_s, 1,
-                                   INT_MAX});
+            (grpc_integer_options){t->is_client
+                                       ? g_default_client_keepalive_time_ms
+                                       : g_default_server_keepalive_time_ms,
+                                   1, INT_MAX});
         t->keepalive_time = value == INT_MAX
                                 ? gpr_inf_future(GPR_TIMESPAN)
-                                : gpr_time_from_seconds(value, GPR_TIMESPAN);
+                                : gpr_time_from_millis(value, GPR_TIMESPAN);
       } else if (0 == strcmp(channel_args->args[i].key,
-                             GRPC_ARG_CLIENT_KEEPALIVE_TIMEOUT_S)) {
+                             GRPC_ARG_KEEPALIVE_TIMEOUT_MS)) {
         const int value = grpc_channel_arg_get_integer(
             &channel_args->args[i],
-            (grpc_integer_options){g_default_client_keepalive_timeout_s, 0,
-                                   INT_MAX});
+            (grpc_integer_options){t->is_client
+                                       ? g_default_client_keepalive_timeout_ms
+                                       : g_default_server_keepalive_timeout_ms,
+                                   0, INT_MAX});
         t->keepalive_timeout = value == INT_MAX
                                    ? gpr_inf_future(GPR_TIMESPAN)
-                                   : gpr_time_from_seconds(value, GPR_TIMESPAN);
+                                   : gpr_time_from_millis(value, GPR_TIMESPAN);
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS)) {
         t->keepalive_permit_without_calls =
@@ -488,8 +532,11 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
       t->ping_policy.max_pings_without_data;
   t->ping_state.is_delayed_ping_timer_set = false;
 
-  /** Start client-side keepalive pings */
-  if (t->is_client) {
+  t->ping_recv_state.last_ping_recv_time = gpr_inf_past(GPR_CLOCK_MONOTONIC);
+  t->ping_recv_state.ping_strikes = 0;
+
+  /* Start keepalive pings */
+  if (gpr_time_cmp(t->keepalive_time, gpr_inf_future(GPR_TIMESPAN)) != 0) {
     t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_WAITING;
     GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
     grpc_timer_init(
@@ -918,6 +965,26 @@ void grpc_chttp2_add_incoming_goaway(grpc_exec_ctx *exec_ctx,
   // GRPC_CHTTP2_IF_TRACING(
   //     gpr_log(GPR_DEBUG, "got goaway [%d]: %s", goaway_error, msg));
   t->seen_goaway = 1;
+
+  /* When a client receives a GOAWAY with error code ENHANCE_YOUR_CALM and debug
+   * data equal to “too_many_pings”, it should log the occurrence at a log level
+   * that is enabled by default and double the configured KEEPALIVE_TIME used
+   * for new connections on that channel. */
+  if (t->is_client && goaway_error == GRPC_HTTP2_ENHANCE_YOUR_CALM &&
+      grpc_slice_str_cmp(goaway_text, "too_many_pings") == 0) {
+    gpr_log(GPR_ERROR,
+            "Received a GOAWAY with error code ENHANCE_YOUR_CALM and debug "
+            "data equal to \"too_many_pings\"");
+    double current_keepalive_time_ms =
+        gpr_timespec_to_micros(t->keepalive_time) / 1000;
+    t->keepalive_time =
+        current_keepalive_time_ms > INT_MAX / KEEPALIVE_TIME_BACKOFF_MULTIPLIER
+            ? gpr_inf_future(GPR_TIMESPAN)
+            : gpr_time_from_millis((int64_t)(current_keepalive_time_ms *
+                                             KEEPALIVE_TIME_BACKOFF_MULTIPLIER),
+                                   GPR_TIMESPAN);
+  }
+
   /* lie: use transient failure from the transport to indicate goaway has been
    * received */
   connectivity_state_set(
@@ -1102,7 +1169,7 @@ static void continue_fetching_send_locked(grpc_exec_ctx *exec_ctx,
       return; /* early out */
     } else if (grpc_byte_stream_next(exec_ctx, s->fetching_send_message,
                                      &s->fetching_slice, UINT32_MAX,
-                                     &s->complete_fetch)) {
+                                     &s->complete_fetch_locked)) {
       add_fetched_slice_locked(exec_ctx, t, s);
     }
   }
@@ -1140,20 +1207,23 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
                                      grpc_error *error_ignored) {
   GPR_TIMER_BEGIN("perform_stream_op_locked", 0);
 
-  grpc_transport_stream_op *op = stream_op;
-  grpc_chttp2_transport *t = op->handler_private.args[0];
-  grpc_chttp2_stream *s = op->handler_private.args[1];
+  grpc_transport_stream_op_batch *op = stream_op;
+  grpc_chttp2_stream *s = op->handler_private.extra_arg;
+  grpc_transport_stream_op_batch_payload *op_payload = op->payload;
+  grpc_chttp2_transport *t = s->t;
 
   if (grpc_http_trace) {
-    char *str = grpc_transport_stream_op_string(op);
+    char *str = grpc_transport_stream_op_batch_string(op);
     gpr_log(GPR_DEBUG, "perform_stream_op_locked: %s; on_complete = %p", str,
             op->on_complete);
     gpr_free(str);
     if (op->send_initial_metadata) {
-      log_metadata(op->send_initial_metadata, s->id, t->is_client, true);
+      log_metadata(op_payload->send_initial_metadata.send_initial_metadata,
+                   s->id, t->is_client, true);
     }
     if (op->send_trailing_metadata) {
-      log_metadata(op->send_trailing_metadata, s->id, t->is_client, false);
+      log_metadata(op_payload->send_trailing_metadata.send_trailing_metadata,
+                   s->id, t->is_client, false);
     }
   }
 
@@ -1168,23 +1238,25 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
   on_complete->next_data.scratch = CLOSURE_BARRIER_FIRST_REF_BIT;
   on_complete->error_data.error = GRPC_ERROR_NONE;
 
-  if (op->collect_stats != NULL) {
+  if (op->collect_stats) {
     GPR_ASSERT(s->collecting_stats == NULL);
-    s->collecting_stats = op->collect_stats;
+    s->collecting_stats = op_payload->collect_stats.collect_stats;
     on_complete->next_data.scratch |= CLOSURE_BARRIER_STATS_BIT;
   }
 
-  if (op->cancel_error != GRPC_ERROR_NONE) {
-    grpc_chttp2_cancel_stream(exec_ctx, t, s, op->cancel_error);
+  if (op->cancel_stream) {
+    grpc_chttp2_cancel_stream(exec_ctx, t, s,
+                              op_payload->cancel_stream.cancel_error);
   }
 
-  if (op->send_initial_metadata != NULL) {
+  if (op->send_initial_metadata) {
     GPR_ASSERT(s->send_initial_metadata_finished == NULL);
     on_complete->next_data.scratch |= CLOSURE_BARRIER_MAY_COVER_WRITE;
     s->send_initial_metadata_finished = add_closure_barrier(on_complete);
-    s->send_initial_metadata = op->send_initial_metadata;
+    s->send_initial_metadata =
+        op_payload->send_initial_metadata.send_initial_metadata;
     const size_t metadata_size =
-        grpc_metadata_batch_size(op->send_initial_metadata);
+        grpc_metadata_batch_size(s->send_initial_metadata);
     const size_t metadata_peer_limit =
         t->settings[GRPC_PEER_SETTINGS]
                    [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
@@ -1205,7 +1277,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
-      if (contains_non_ok_status(op->send_initial_metadata)) {
+      if (contains_non_ok_status(s->send_initial_metadata)) {
         s->seen_error = true;
       }
       if (!s->write_closed) {
@@ -1225,8 +1297,9 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
           GPR_ASSERT(s->id != 0);
           grpc_chttp2_stream_write_type write_type =
               GRPC_CHTTP2_STREAM_WRITE_INITIATE_COVERED;
-          if (op->send_message != NULL &&
-              (op->send_message->flags & GRPC_WRITE_BUFFER_HINT)) {
+          if (op->send_message &&
+              (op->payload->send_message.send_message->flags &
+               GRPC_WRITE_BUFFER_HINT)) {
             write_type = GRPC_CHTTP2_STREAM_WRITE_PIGGYBACK;
           }
           grpc_chttp2_become_writable(exec_ctx, t, s, write_type,
@@ -1244,7 +1317,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     }
   }
 
-  if (op->send_message != NULL) {
+  if (op->send_message) {
     on_complete->next_data.scratch |= CLOSURE_BARRIER_MAY_COVER_WRITE;
     s->fetching_send_message_finished = add_closure_barrier(op->on_complete);
     if (s->write_closed) {
@@ -1258,14 +1331,14 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
       GPR_ASSERT(s->fetching_send_message == NULL);
       uint8_t *frame_hdr =
           grpc_slice_buffer_tiny_add(&s->flow_controlled_buffer, 5);
-      uint32_t flags = op->send_message->flags;
+      uint32_t flags = op_payload->send_message.send_message->flags;
       frame_hdr[0] = (flags & GRPC_WRITE_INTERNAL_COMPRESS) != 0;
-      size_t len = op->send_message->length;
+      size_t len = op_payload->send_message.send_message->length;
       frame_hdr[1] = (uint8_t)(len >> 24);
       frame_hdr[2] = (uint8_t)(len >> 16);
       frame_hdr[3] = (uint8_t)(len >> 8);
       frame_hdr[4] = (uint8_t)(len);
-      s->fetching_send_message = op->send_message;
+      s->fetching_send_message = op_payload->send_message.send_message;
       s->fetched_send_message_length = 0;
       s->next_message_end_offset = s->flow_controlled_bytes_written +
                                    (int64_t)s->flow_controlled_buffer.length +
@@ -1282,14 +1355,15 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     }
   }
 
-  if (op->send_trailing_metadata != NULL) {
+  if (op->send_trailing_metadata) {
     GPR_ASSERT(s->send_trailing_metadata_finished == NULL);
     on_complete->next_data.scratch |= CLOSURE_BARRIER_MAY_COVER_WRITE;
     s->send_trailing_metadata_finished = add_closure_barrier(on_complete);
-    s->send_trailing_metadata = op->send_trailing_metadata;
+    s->send_trailing_metadata =
+        op_payload->send_trailing_metadata.send_trailing_metadata;
     s->write_buffering = false;
     const size_t metadata_size =
-        grpc_metadata_batch_size(op->send_trailing_metadata);
+        grpc_metadata_batch_size(s->send_trailing_metadata);
     const size_t metadata_peer_limit =
         t->settings[GRPC_PEER_SETTINGS]
                    [GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE];
@@ -1306,14 +1380,15 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
                   GRPC_ERROR_INT_LIMIT, (intptr_t)metadata_peer_limit),
               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_RESOURCE_EXHAUSTED));
     } else {
-      if (contains_non_ok_status(op->send_trailing_metadata)) {
+      if (contains_non_ok_status(s->send_trailing_metadata)) {
         s->seen_error = true;
       }
       if (s->write_closed) {
         s->send_trailing_metadata = NULL;
         grpc_chttp2_complete_closure_step(
             exec_ctx, t, s, &s->send_trailing_metadata_finished,
-            grpc_metadata_batch_is_empty(op->send_trailing_metadata)
+            grpc_metadata_batch_is_empty(
+                op->payload->send_trailing_metadata.send_trailing_metadata)
                 ? GRPC_ERROR_NONE
                 : GRPC_ERROR_CREATE_FROM_STATIC_STRING(
                       "Attempt to send trailing metadata after "
@@ -1329,17 +1404,19 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     }
   }
 
-  if (op->recv_initial_metadata != NULL) {
+  if (op->recv_initial_metadata) {
     GPR_ASSERT(s->recv_initial_metadata_ready == NULL);
-    s->recv_initial_metadata_ready = op->recv_initial_metadata_ready;
-    s->recv_initial_metadata = op->recv_initial_metadata;
+    s->recv_initial_metadata_ready =
+        op_payload->recv_initial_metadata.recv_initial_metadata_ready;
+    s->recv_initial_metadata =
+        op_payload->recv_initial_metadata.recv_initial_metadata;
     grpc_chttp2_maybe_complete_recv_initial_metadata(exec_ctx, t, s);
   }
 
-  if (op->recv_message != NULL) {
+  if (op->recv_message) {
     GPR_ASSERT(s->recv_message_ready == NULL);
-    s->recv_message_ready = op->recv_message_ready;
-    s->recv_message = op->recv_message;
+    s->recv_message_ready = op_payload->recv_message.recv_message_ready;
+    s->recv_message = op_payload->recv_message.recv_message;
     if (s->id != 0 &&
         (s->incoming_frames.head == NULL || s->incoming_frames.head->is_tail)) {
       incoming_byte_stream_update_flow_control(exec_ctx, t, s, 5, 0);
@@ -1347,10 +1424,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
   }
 
-  if (op->recv_trailing_metadata != NULL) {
+  if (op->recv_trailing_metadata) {
     GPR_ASSERT(s->recv_trailing_metadata_finished == NULL);
     s->recv_trailing_metadata_finished = add_closure_barrier(on_complete);
-    s->recv_trailing_metadata = op->recv_trailing_metadata;
+    s->recv_trailing_metadata =
+        op_payload->recv_trailing_metadata.recv_trailing_metadata;
     s->final_metadata_requested = true;
     grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
@@ -1363,19 +1441,19 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
 }
 
 static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
-                              grpc_stream *gs, grpc_transport_stream_op *op) {
+                              grpc_stream *gs,
+                              grpc_transport_stream_op_batch *op) {
   GPR_TIMER_BEGIN("perform_stream_op", 0);
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)gt;
   grpc_chttp2_stream *s = (grpc_chttp2_stream *)gs;
 
   if (grpc_http_trace) {
-    char *str = grpc_transport_stream_op_string(op);
+    char *str = grpc_transport_stream_op_batch_string(op);
     gpr_log(GPR_DEBUG, "perform_stream_op[s=%p/%d]: %s", s, s->id, str);
     gpr_free(str);
   }
 
-  op->handler_private.args[0] = gt;
-  op->handler_private.args[1] = gs;
+  op->handler_private.extra_arg = gs;
   GRPC_CHTTP2_STREAM_REF(s, "perform_stream_op");
   grpc_closure_sched(
       exec_ctx,
@@ -1448,11 +1526,26 @@ static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   GRPC_ERROR_UNREF(error);
 }
 
+void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t) {
+  gpr_log(GPR_DEBUG, "PING strike");
+  if (++t->ping_recv_state.ping_strikes > t->ping_policy.max_ping_strikes &&
+      t->ping_policy.max_ping_strikes != 0) {
+    send_goaway(exec_ctx, t,
+                grpc_error_set_int(
+                    GRPC_ERROR_CREATE_FROM_STATIC_STRING("too_many_pings"),
+                    GRPC_ERROR_INT_HTTP2_ERROR, GRPC_HTTP2_ENHANCE_YOUR_CALM));
+    /*The transport will be closed after the write is done */
+    close_transport_locked(
+        exec_ctx, t, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Too many pings"));
+  }
+}
+
 static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
                                         void *stream_op,
                                         grpc_error *error_ignored) {
   grpc_transport_op *op = stream_op;
-  grpc_chttp2_transport *t = op->transport_private.args[0];
+  grpc_chttp2_transport *t = op->handler_private.extra_arg;
   grpc_error *close_transport = op->disconnect_with_error;
 
   if (op->on_connectivity_state_change != NULL) {
@@ -1498,10 +1591,10 @@ static void perform_transport_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
   grpc_chttp2_transport *t = (grpc_chttp2_transport *)gt;
   char *msg = grpc_transport_op_string(op);
   gpr_free(msg);
-  op->transport_private.args[0] = gt;
+  op->handler_private.extra_arg = gt;
   GRPC_CHTTP2_REF_TRANSPORT(t, "transport_op");
   grpc_closure_sched(
-      exec_ctx, grpc_closure_init(&op->transport_private.closure,
+      exec_ctx, grpc_closure_init(&op->handler_private.closure,
                                   perform_transport_op_locked, op,
                                   grpc_combiner_scheduler(t->combiner, false)),
       GRPC_ERROR_NONE);
@@ -2114,6 +2207,10 @@ static void start_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
   if (grpc_http_trace) {
     gpr_log(GPR_DEBUG, "%s: Start BDP ping", t->peer_string);
   }
+  /* Reset the keepalive ping timer */
+  if (t->keepalive_state == GRPC_CHTTP2_KEEPALIVE_STATE_WAITING) {
+    grpc_timer_cancel(exec_ctx, &t->keepalive_ping_timer);
+  }
   grpc_bdp_estimator_start_ping(&t->bdp_estimator);
 }
 
@@ -2128,20 +2225,32 @@ static void finish_bdp_ping_locked(grpc_exec_ctx *exec_ctx, void *tp,
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "bdp_ping");
 }
 
-void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args) {
+void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
+                                               bool is_client) {
   size_t i;
   if (args) {
     for (i = 0; i < args->num_args; i++) {
-      if (0 == strcmp(args->args[i].key, GRPC_ARG_CLIENT_KEEPALIVE_TIME_S)) {
-        g_default_client_keepalive_time_s = grpc_channel_arg_get_integer(
-            &args->args[i], (grpc_integer_options){
-                                g_default_client_keepalive_time_s, 1, INT_MAX});
-      } else if (0 == strcmp(args->args[i].key,
-                             GRPC_ARG_CLIENT_KEEPALIVE_TIMEOUT_S)) {
-        g_default_client_keepalive_timeout_s = grpc_channel_arg_get_integer(
+      if (0 == strcmp(args->args[i].key, GRPC_ARG_KEEPALIVE_TIME_MS)) {
+        const int value = grpc_channel_arg_get_integer(
+            &args->args[i],
+            (grpc_integer_options){g_default_client_keepalive_time_ms, 1,
+                                   INT_MAX});
+        if (is_client) {
+          g_default_client_keepalive_time_ms = value;
+        } else {
+          g_default_server_keepalive_time_ms = value;
+        }
+      } else if (0 ==
+                 strcmp(args->args[i].key, GRPC_ARG_KEEPALIVE_TIMEOUT_MS)) {
+        const int value = grpc_channel_arg_get_integer(
             &args->args[i],
-            (grpc_integer_options){g_default_client_keepalive_timeout_s, 0,
+            (grpc_integer_options){g_default_client_keepalive_timeout_ms, 0,
                                    INT_MAX});
+        if (is_client) {
+          g_default_client_keepalive_timeout_ms = value;
+        } else {
+          g_default_server_keepalive_timeout_ms = value;
+        }
       } else if (0 == strcmp(args->args[i].key,
                              GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS)) {
         g_default_keepalive_permit_without_calls =
@@ -2159,7 +2268,8 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_chttp2_transport *t = arg;
   GPR_ASSERT(t->keepalive_state == GRPC_CHTTP2_KEEPALIVE_STATE_WAITING);
   if (error == GRPC_ERROR_NONE && !(t->destroying || t->closed)) {
-    if (t->keepalive_permit_without_calls || t->stream_map.count > 0) {
+    if (t->keepalive_permit_without_calls ||
+        grpc_chttp2_stream_map_size(&t->stream_map) > 0) {
       t->keepalive_state = GRPC_CHTTP2_KEEPALIVE_STATE_PINGING;
       GRPC_CHTTP2_REF_TRANSPORT(t, "keepalive ping end");
       send_ping_locked(exec_ctx, t, GRPC_CHTTP2_PING_ON_NEXT_WRITE,
@@ -2172,6 +2282,13 @@ static void init_keepalive_ping_locked(grpc_exec_ctx *exec_ctx, void *arg,
           gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
           &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
     }
+  } else if (error == GRPC_ERROR_CANCELLED && !(t->destroying || t->closed)) {
+    /* The keepalive ping timer may be cancelled by bdp */
+    GRPC_CHTTP2_REF_TRANSPORT(t, "init keepalive ping");
+    grpc_timer_init(
+        exec_ctx, &t->keepalive_ping_timer,
+        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), t->keepalive_time),
+        &t->init_keepalive_ping_locked, gpr_now(GPR_CLOCK_MONOTONIC));
   }
   GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "init keepalive ping");
 }
@@ -2213,8 +2330,8 @@ static void keepalive_watchdog_fired_locked(grpc_exec_ctx *exec_ctx, void *arg,
                                               "keepalive watchdog timeout"));
     }
   } else {
-    /** The watchdog timer should have been cancelled by
-        finish_keepalive_ping_locked. */
+    /* The watchdog timer should have been cancelled by
+     * finish_keepalive_ping_locked. */
     if (error != GRPC_ERROR_CANCELLED) {
       gpr_log(GPR_ERROR, "keepalive_ping_end state error: %d (expect: %d)",
               t->keepalive_state, GRPC_CHTTP2_KEEPALIVE_STATE_PINGING);
diff --git a/src/core/ext/transport/chttp2/transport/frame_ping.c b/src/core/ext/transport/chttp2/transport/frame_ping.c
index 46dafdb62f..6016e43127 100644
--- a/src/core/ext/transport/chttp2/transport/frame_ping.c
+++ b/src/core/ext/transport/chttp2/transport/frame_ping.c
@@ -103,6 +103,28 @@ grpc_error *grpc_chttp2_ping_parser_parse(grpc_exec_ctx *exec_ctx, void *parser,
     if (p->is_ack) {
       grpc_chttp2_ack_ping(exec_ctx, t, p->opaque_8bytes);
     } else {
+      if (!t->is_client) {
+        gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
+        gpr_timespec next_allowed_ping =
+            gpr_time_add(t->ping_recv_state.last_ping_recv_time,
+                         t->ping_policy.min_ping_interval_without_data);
+
+        if (t->keepalive_permit_without_calls == 0 &&
+            grpc_chttp2_stream_map_size(&t->stream_map) == 0) {
+          /* According to RFC1122, the interval of TCP Keep-Alive is default to
+             no less than two hours. When there is no outstanding streams, we
+             restrict the number of PINGS equivalent to TCP Keep-Alive. */
+          next_allowed_ping =
+              gpr_time_add(t->ping_recv_state.last_ping_recv_time,
+                           gpr_time_from_seconds(7200, GPR_TIMESPAN));
+        }
+
+        if (gpr_time_cmp(next_allowed_ping, now) > 0) {
+          grpc_chttp2_add_ping_strike(exec_ctx, t);
+        }
+
+        t->ping_recv_state.last_ping_recv_time = now;
+      }
       if (!g_disable_ping_ack) {
         if (t->ping_ack_count == t->ping_ack_capacity) {
           t->ping_ack_capacity = GPR_MAX(t->ping_ack_capacity * 3 / 2, 3);
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 8b718e963c..6eb848b8d7 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -97,6 +97,8 @@ typedef struct {
 typedef struct {
   gpr_timespec min_time_between_pings;
   int max_pings_without_data;
+  int max_ping_strikes;
+  gpr_timespec min_ping_interval_without_data;
 } grpc_chttp2_repeated_ping_policy;
 
 typedef struct {
@@ -106,6 +108,11 @@ typedef struct {
   bool is_delayed_ping_timer_set;
 } grpc_chttp2_repeated_ping_state;
 
+typedef struct {
+  gpr_timespec last_ping_recv_time;
+  int ping_strikes;
+} grpc_chttp2_server_ping_recv_state;
+
 /* deframer state for the overall http2 stream of bytes */
 typedef enum {
   /* prefix: one entry per http2 connection prefix byte */
@@ -316,6 +323,7 @@ struct grpc_chttp2_transport {
   size_t ping_ack_count;
   size_t ping_ack_capacity;
   uint64_t *ping_acks;
+  grpc_chttp2_server_ping_recv_state ping_recv_state;
 
   /** parser for headers */
   grpc_chttp2_hpack_parser hpack_parser;
@@ -452,7 +460,6 @@ struct grpc_chttp2_stream {
   int64_t next_message_end_offset;
   int64_t flow_controlled_bytes_written;
   bool complete_fetch_covered_by_poller;
-  grpc_closure complete_fetch;
   grpc_closure complete_fetch_locked;
   grpc_closure *fetching_send_message_finished;
 
@@ -793,6 +800,13 @@ void grpc_chttp2_incoming_byte_stream_finished(
 void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
                           uint64_t id);
 
+/** Add a new ping strike to ping_recv_state.ping_strikes. If
+    ping_recv_state.ping_strikes > ping_policy.max_ping_strikes, it sends GOAWAY
+    with error code ENHANCE_YOUR_CALM and additional debug data resembling
+    “too_many_pings” followed by immediately closing the connection. */
+void grpc_chttp2_add_ping_strike(grpc_exec_ctx *exec_ctx,
+                                 grpc_chttp2_transport *t);
+
 typedef enum {
   /* don't initiate a transport write, but piggyback on the next one */
   GRPC_CHTTP2_STREAM_WRITE_PIGGYBACK,
@@ -832,6 +846,7 @@ uint32_t grpc_chttp2_target_incoming_window(grpc_chttp2_transport *t);
 
 /** Set the default keepalive configurations, must only be called at
     initialization */
-void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args);
+void grpc_chttp2_config_default_keepalive_args(grpc_channel_args *args,
+                                               bool is_client);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_INTERNAL_H */
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 0869056f56..be41b3d186 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -229,6 +229,11 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
       now_writing = true;
       t->ping_state.pings_before_data_required =
           t->ping_policy.max_pings_without_data;
+      if (!t->is_client) {
+        t->ping_recv_state.last_ping_recv_time =
+            gpr_inf_past(GPR_CLOCK_MONOTONIC);
+        t->ping_recv_state.ping_strikes = 0;
+      }
     }
     /* send any window updates */
     if (s->announce_window > 0) {
@@ -238,6 +243,11 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
                                 s->id, s->announce_window, &s->stats.outgoing));
       t->ping_state.pings_before_data_required =
           t->ping_policy.max_pings_without_data;
+      if (!t->is_client) {
+        t->ping_recv_state.last_ping_recv_time =
+            gpr_inf_past(GPR_CLOCK_MONOTONIC);
+        t->ping_recv_state.ping_strikes = 0;
+      }
       GRPC_CHTTP2_FLOW_DEBIT_STREAM("write", t, s, announce_window, announce);
     }
     if (sent_initial_metadata) {
@@ -270,6 +280,11 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
                                            send_bytes);
           t->ping_state.pings_before_data_required =
               t->ping_policy.max_pings_without_data;
+          if (!t->is_client) {
+            t->ping_recv_state.last_ping_recv_time =
+                gpr_inf_past(GPR_CLOCK_MONOTONIC);
+            t->ping_recv_state.ping_strikes = 0;
+          }
           if (is_last_frame) {
             s->send_trailing_metadata = NULL;
             s->sent_trailing_metadata = true;
@@ -345,6 +360,11 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
                                           0, announced, &throwaway_stats));
     t->ping_state.pings_before_data_required =
         t->ping_policy.max_pings_without_data;
+    if (!t->is_client) {
+      t->ping_recv_state.last_ping_recv_time =
+          gpr_inf_past(GPR_CLOCK_MONOTONIC);
+      t->ping_recv_state.ping_strikes = 0;
+    }
   }
 
   for (size_t i = 0; i < t->ping_ack_count; i++) {
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index 952690eba7..0b9189558f 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -172,7 +172,7 @@ struct op_state {
 };
 
 struct op_and_state {
-  grpc_transport_stream_op op;
+  grpc_transport_stream_op_batch op;
   struct op_state state;
   bool done;
   struct stream_obj *s;      /* Pointer back to the stream object */
@@ -187,7 +187,7 @@ struct op_storage {
 struct stream_obj {
   gpr_arena *arena;
   struct op_and_state *oas;
-  grpc_transport_stream_op *curr_op;
+  grpc_transport_stream_op_batch *curr_op;
   grpc_cronet_transport *curr_ct;
   grpc_stream *curr_gs;
   bidirectional_stream *cbs;
@@ -298,12 +298,13 @@ static grpc_error *make_error_with_desc(int error_code, const char *desc) {
 /*
   Add a new stream op to op storage.
 */
-static void add_to_storage(struct stream_obj *s, grpc_transport_stream_op *op) {
+static void add_to_storage(struct stream_obj *s,
+                           grpc_transport_stream_op_batch *op) {
   struct op_storage *storage = &s->storage;
   /* add new op at the beginning of the linked list. The memory is freed
   in remove_from_storage */
   struct op_and_state *new_op = gpr_malloc(sizeof(struct op_and_state));
-  memcpy(&new_op->op, op, sizeof(grpc_transport_stream_op));
+  memcpy(&new_op->op, op, sizeof(grpc_transport_stream_op_batch));
   memset(&new_op->state, 0, sizeof(new_op->state));
   new_op->s = s;
   new_op->done = false;
@@ -768,7 +769,7 @@ static bool header_has_authority(grpc_linked_mdelem *head) {
   Op Execution: Decide if one of the actions contained in the stream op can be
   executed. This is the heart of the state machine.
 */
-static bool op_can_be_run(grpc_transport_stream_op *curr_op,
+static bool op_can_be_run(grpc_transport_stream_op_batch *curr_op,
                           struct stream_obj *s, struct op_state *op_state,
                           enum e_op_id op_id) {
   struct op_state *stream_state = &s->state;
@@ -919,7 +920,7 @@ static bool op_can_be_run(grpc_transport_stream_op *curr_op,
 */
 static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
                                           struct op_and_state *oas) {
-  grpc_transport_stream_op *stream_op = &oas->op;
+  grpc_transport_stream_op_batch *stream_op = &oas->op;
   struct stream_obj *s = oas->s;
   grpc_cronet_transport *t = (grpc_cronet_transport *)s->curr_ct;
   struct op_state *stream_state = &s->state;
@@ -941,9 +942,10 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
     char *url = NULL;
     const char *method = "POST";
     s->header_array.headers = NULL;
-    convert_metadata_to_cronet_headers(
-        stream_op->send_initial_metadata->list.head, t->host, &url,
-        &s->header_array.headers, &s->header_array.count, &method);
+    convert_metadata_to_cronet_headers(stream_op->payload->send_initial_metadata
+                                           .send_initial_metadata->list.head,
+                                       t->host, &url, &s->header_array.headers,
+                                       &s->header_array.count, &method);
     s->header_array.capacity = s->header_array.count;
     CRONET_LOG(GPR_DEBUG, "bidirectional_stream_start(%p, %s)", s->cbs, url);
     bidirectional_stream_start(s->cbs, url, 0, method, &s->header_array, false);
@@ -971,8 +973,9 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
       grpc_slice_buffer write_slice_buffer;
       grpc_slice slice;
       grpc_slice_buffer_init(&write_slice_buffer);
-      grpc_byte_stream_next(NULL, stream_op->send_message, &slice,
-                            stream_op->send_message->length, NULL);
+      grpc_byte_stream_next(
+          NULL, stream_op->payload->send_message.send_message, &slice,
+          stream_op->payload->send_message.send_message->length, NULL);
       grpc_slice_buffer_add(&write_slice_buffer, slice);
       if (write_slice_buffer.count != 1) {
         /* Empty request not handled yet */
@@ -982,7 +985,8 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
       if (write_slice_buffer.count > 0) {
         size_t write_buffer_size;
         create_grpc_frame(&write_slice_buffer, &stream_state->ws.write_buffer,
-                          &write_buffer_size, stream_op->send_message->flags);
+                          &write_buffer_size,
+                          stream_op->payload->send_message.send_message->flags);
         CRONET_LOG(GPR_DEBUG, "bidirectional_stream_write (%p, %p)", s->cbs,
                    stream_state->ws.write_buffer);
         stream_state->state_callback_received[OP_SEND_MESSAGE] = false;
@@ -1029,20 +1033,28 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
                            OP_RECV_INITIAL_METADATA)) {
     CRONET_LOG(GPR_DEBUG, "running: %p  OP_RECV_INITIAL_METADATA", oas);
     if (stream_state->state_op_done[OP_CANCEL_ERROR]) {
-      grpc_closure_sched(exec_ctx, stream_op->recv_initial_metadata_ready,
-                         GRPC_ERROR_NONE);
+      grpc_closure_sched(
+          exec_ctx,
+          stream_op->payload->recv_initial_metadata.recv_initial_metadata_ready,
+          GRPC_ERROR_NONE);
     } else if (stream_state->state_callback_received[OP_FAILED]) {
-      grpc_closure_sched(exec_ctx, stream_op->recv_initial_metadata_ready,
-                         GRPC_ERROR_NONE);
+      grpc_closure_sched(
+          exec_ctx,
+          stream_op->payload->recv_initial_metadata.recv_initial_metadata_ready,
+          GRPC_ERROR_NONE);
     } else if (stream_state->state_op_done[OP_RECV_TRAILING_METADATA]) {
-      grpc_closure_sched(exec_ctx, stream_op->recv_initial_metadata_ready,
-                         GRPC_ERROR_NONE);
+      grpc_closure_sched(
+          exec_ctx,
+          stream_op->payload->recv_initial_metadata.recv_initial_metadata_ready,
+          GRPC_ERROR_NONE);
     } else {
       grpc_chttp2_incoming_metadata_buffer_publish(
           exec_ctx, &oas->s->state.rs.initial_metadata,
-          stream_op->recv_initial_metadata);
-      grpc_closure_sched(exec_ctx, stream_op->recv_initial_metadata_ready,
-                         GRPC_ERROR_NONE);
+          stream_op->payload->recv_initial_metadata.recv_initial_metadata);
+      grpc_closure_sched(
+          exec_ctx,
+          stream_op->payload->recv_initial_metadata.recv_initial_metadata_ready,
+          GRPC_ERROR_NONE);
     }
     stream_state->state_op_done[OP_RECV_INITIAL_METADATA] = true;
     result = ACTION_TAKEN_NO_CALLBACK;
@@ -1051,27 +1063,31 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
     CRONET_LOG(GPR_DEBUG, "running: %p  OP_RECV_MESSAGE", oas);
     if (stream_state->state_op_done[OP_CANCEL_ERROR]) {
       CRONET_LOG(GPR_DEBUG, "Stream is cancelled.");
-      grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
+      grpc_closure_sched(exec_ctx,
+                         stream_op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_NONE);
       stream_state->state_op_done[OP_RECV_MESSAGE] = true;
       result = ACTION_TAKEN_NO_CALLBACK;
     } else if (stream_state->state_callback_received[OP_FAILED]) {
       CRONET_LOG(GPR_DEBUG, "Stream failed.");
-      grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
+      grpc_closure_sched(exec_ctx,
+                         stream_op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_NONE);
       stream_state->state_op_done[OP_RECV_MESSAGE] = true;
       result = ACTION_TAKEN_NO_CALLBACK;
     } else if (stream_state->rs.read_stream_closed == true) {
       /* No more data will be received */
       CRONET_LOG(GPR_DEBUG, "read stream closed");
-      grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
+      grpc_closure_sched(exec_ctx,
+                         stream_op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_NONE);
       stream_state->state_op_done[OP_RECV_MESSAGE] = true;
       oas->state.state_op_done[OP_RECV_MESSAGE] = true;
       result = ACTION_TAKEN_NO_CALLBACK;
     } else if (stream_state->flush_read) {
       CRONET_LOG(GPR_DEBUG, "flush read");
-      grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
+      grpc_closure_sched(exec_ctx,
+                         stream_op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_NONE);
       stream_state->state_op_done[OP_RECV_MESSAGE] = true;
       oas->state.state_op_done[OP_RECV_MESSAGE] = true;
@@ -1110,8 +1126,9 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
           }
           *((grpc_byte_buffer **)stream_op->recv_message) =
               (grpc_byte_buffer *)&stream_state->rs.sbs;
-          grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
-                             GRPC_ERROR_NONE);
+          grpc_closure_sched(
+              exec_ctx, stream_op->payload->recv_message.recv_message_ready,
+              GRPC_ERROR_NONE);
           stream_state->state_op_done[OP_RECV_MESSAGE] = true;
           oas->state.state_op_done[OP_RECV_MESSAGE] = true;
 
@@ -1161,9 +1178,10 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
       if (stream_state->rs.compressed) {
         stream_state->rs.sbs.base.flags = GRPC_WRITE_INTERNAL_COMPRESS;
       }
-      *((grpc_byte_buffer **)stream_op->recv_message) =
+      *((grpc_byte_buffer **)stream_op->payload->recv_message.recv_message) =
           (grpc_byte_buffer *)&stream_state->rs.sbs;
-      grpc_closure_sched(exec_ctx, stream_op->recv_message_ready,
+      grpc_closure_sched(exec_ctx,
+                         stream_op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_NONE);
       stream_state->state_op_done[OP_RECV_MESSAGE] = true;
       oas->state.state_op_done[OP_RECV_MESSAGE] = true;
@@ -1187,12 +1205,12 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
     if (oas->s->state.rs.trailing_metadata_valid) {
       grpc_chttp2_incoming_metadata_buffer_publish(
           exec_ctx, &oas->s->state.rs.trailing_metadata,
-          stream_op->recv_trailing_metadata);
+          stream_op->payload->recv_trailing_metadata.recv_trailing_metadata);
       stream_state->rs.trailing_metadata_valid = false;
     }
     stream_state->state_op_done[OP_RECV_TRAILING_METADATA] = true;
     result = ACTION_TAKEN_NO_CALLBACK;
-  } else if (stream_op->cancel_error &&
+  } else if (stream_op->cancel_stream &&
              op_can_be_run(stream_op, s, &oas->state, OP_CANCEL_ERROR)) {
     CRONET_LOG(GPR_DEBUG, "running: %p  OP_CANCEL_ERROR", oas);
     CRONET_LOG(GPR_DEBUG, "W: bidirectional_stream_cancel(%p)", s->cbs);
@@ -1204,7 +1222,8 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
     }
     stream_state->state_op_done[OP_CANCEL_ERROR] = true;
     if (!stream_state->cancel_error) {
-      stream_state->cancel_error = GRPC_ERROR_REF(stream_op->cancel_error);
+      stream_state->cancel_error =
+          GRPC_ERROR_REF(stream_op->payload->cancel_stream.cancel_error);
     }
   } else if (stream_op->on_complete &&
              op_can_be_run(stream_op, s, &oas->state, OP_ON_COMPLETE)) {
@@ -1283,18 +1302,22 @@ static void set_pollset_set_do_nothing(grpc_exec_ctx *exec_ctx,
                                        grpc_pollset_set *pollset_set) {}
 
 static void perform_stream_op(grpc_exec_ctx *exec_ctx, grpc_transport *gt,
-                              grpc_stream *gs, grpc_transport_stream_op *op) {
+                              grpc_stream *gs,
+                              grpc_transport_stream_op_batch *op) {
   CRONET_LOG(GPR_DEBUG, "perform_stream_op");
   if (op->send_initial_metadata &&
-      header_has_authority(op->send_initial_metadata->list.head)) {
+      header_has_authority(op->payload->send_initial_metadata
+                               .send_initial_metadata->list.head)) {
     /* Cronet does not support :authority header field. We cancel the call when
      this field is present in metadata */
-    if (op->recv_initial_metadata_ready) {
-      grpc_closure_sched(exec_ctx, op->recv_initial_metadata_ready,
-                         GRPC_ERROR_CANCELLED);
+    if (op->recv_initial_metadata) {
+      grpc_closure_sched(
+          exec_ctx,
+          op->payload->recv_initial_metadata.recv_initial_metadata_ready,
+          GRPC_ERROR_CANCELLED);
     }
-    if (op->recv_message_ready) {
-      grpc_closure_sched(exec_ctx, op->recv_message_ready,
+    if (op->recv_message) {
+      grpc_closure_sched(exec_ctx, op->payload->recv_message.recv_message_ready,
                          GRPC_ERROR_CANCELLED);
     }
     grpc_closure_sched(exec_ctx, op->on_complete, GRPC_ERROR_CANCELLED);