diff --git a/src/core/client_config/connector.c b/src/core/client_config/connector.c
index 1603ffb8be0..eaa215fe8f6 100644
--- a/src/core/client_config/connector.c
+++ b/src/core/client_config/connector.c
@@ -33,8 +33,9 @@
 
 #include "src/core/client_config/connector.h"
 
-void grpc_connector_ref(grpc_connector* connector) {
+grpc_connector *grpc_connector_ref(grpc_connector* connector) {
   connector->vtable->ref(connector);
+  return connector;
 }
 
 void grpc_connector_unref(grpc_exec_ctx* exec_ctx, grpc_connector* connector) {
diff --git a/src/core/client_config/connector.h b/src/core/client_config/connector.h
index b4482fa2eeb..b301e1bb197 100644
--- a/src/core/client_config/connector.h
+++ b/src/core/client_config/connector.h
@@ -81,7 +81,7 @@ struct grpc_connector_vtable {
                   grpc_connect_out_args *out_args, grpc_closure *notify);
 };
 
-void grpc_connector_ref(grpc_connector *connector);
+grpc_connector *grpc_connector_ref(grpc_connector *connector);
 void grpc_connector_unref(grpc_exec_ctx *exec_ctx, grpc_connector *connector);
 /** Connect using the connector: max one outstanding call at a time */
 void grpc_connector_connect(grpc_exec_ctx *exec_ctx, grpc_connector *connector,
diff --git a/src/core/client_config/subchannel.c b/src/core/client_config/subchannel.c
index 9f287c4b03d..bf2f15a4443 100644
--- a/src/core/client_config/subchannel.c
+++ b/src/core/client_config/subchannel.c
@@ -42,11 +42,11 @@
 #include "src/core/channel/client_channel.h"
 #include "src/core/channel/connected_channel.h"
 #include "src/core/client_config/initial_connect_string.h"
+#include "src/core/client_config/subchannel_index.h"
 #include "src/core/iomgr/timer.h"
 #include "src/core/profiling/timers.h"
 #include "src/core/surface/channel.h"
 #include "src/core/transport/connectivity_state.h"
-#include "src/core/transport/connectivity_state.h"
 
 #define INTERNAL_REF_BITS 16
 #define STRONG_REF_MASK (~(gpr_atm)((1 << INTERNAL_REF_BITS) - 1))
@@ -95,6 +95,8 @@ struct grpc_subchannel {
   struct sockaddr *addr;
   size_t addr_len;
 
+  grpc_subchannel_key *key;
+
   /** initial string to send to peer */
   gpr_slice initial_connect_string;
 
@@ -239,6 +241,7 @@ void grpc_subchannel_weak_ref(grpc_subchannel *c
 
 static void disconnect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
   grpc_connected_subchannel *con;
+  grpc_subchannel_index_unregister(exec_ctx, c->key, c);
   gpr_mu_lock(&c->mu);
   GPR_ASSERT(!c->disconnected);
   c->disconnected = 1;
@@ -277,10 +280,19 @@ static uint32_t random_seed() {
   return (uint32_t)(gpr_time_to_millis(gpr_now(GPR_CLOCK_MONOTONIC)));
 }
 
-grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
+grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
+                                        grpc_connector *connector,
                                         grpc_subchannel_args *args) {
-  grpc_subchannel *c = gpr_malloc(sizeof(*c));
+  grpc_subchannel_key *key = grpc_subchannel_key_create(connector, args);
+  grpc_subchannel *c = grpc_subchannel_index_find(exec_ctx, key);
+  if (c) {
+    grpc_subchannel_key_destroy(key);
+    return c;
+  }
+
+  c = gpr_malloc(sizeof(*c));
   memset(c, 0, sizeof(*c));
+  c->key = key;
   gpr_atm_no_barrier_store(&c->ref_pair, 1 << INTERNAL_REF_BITS);
   c->connector = connector;
   grpc_connector_ref(c->connector);
@@ -302,7 +314,8 @@ grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
   grpc_connectivity_state_init(&c->state_tracker, GRPC_CHANNEL_IDLE,
                                "subchannel");
   gpr_mu_init(&c->mu);
-  return c;
+
+  return grpc_subchannel_index_register(exec_ctx, key, c);
 }
 
 static void continue_connect(grpc_exec_ctx *exec_ctx, grpc_subchannel *c) {
diff --git a/src/core/client_config/subchannel.h b/src/core/client_config/subchannel.h
index 57c7c9dc674..8fd976276b5 100644
--- a/src/core/client_config/subchannel.h
+++ b/src/core/client_config/subchannel.h
@@ -48,6 +48,8 @@ typedef struct grpc_subchannel_args grpc_subchannel_args;
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 #define GRPC_SUBCHANNEL_REF(p, r) \
   grpc_subchannel_ref((p), __FILE__, __LINE__, (r))
+#define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) \
+  grpc_subchannel_ref_from_weak_ref((p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_UNREF(cl, p, r) \
   grpc_subchannel_unref((cl), (p), __FILE__, __LINE__, (r))
 #define GRPC_SUBCHANNEL_WEAK_REF(p, r) \
@@ -66,6 +68,7 @@ typedef struct grpc_subchannel_args grpc_subchannel_args;
   , const char *file, int line, const char *reason
 #else
 #define GRPC_SUBCHANNEL_REF(p, r) grpc_subchannel_ref((p))
+#define GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(p, r) grpc_subchannel_ref_from_weak_ref((p))
 #define GRPC_SUBCHANNEL_UNREF(cl, p, r) grpc_subchannel_unref((cl), (p))
 #define GRPC_SUBCHANNEL_WEAK_REF(p, r) grpc_subchannel_weak_ref((p))
 #define GRPC_SUBCHANNEL_WEAK_UNREF(cl, p, r) \
@@ -146,6 +149,8 @@ grpc_call_stack *grpc_subchannel_call_get_call_stack(
     grpc_subchannel_call *subchannel_call);
 
 struct grpc_subchannel_args {
+  /* When updating this struct, also update subchannel_index.c */
+  
   /** Channel filters for this channel - wrapped factories will likely
       want to mutate this */
   const grpc_channel_filter **filters;
@@ -159,7 +164,8 @@ struct grpc_subchannel_args {
 };
 
 /** create a subchannel given a connector */
-grpc_subchannel *grpc_subchannel_create(grpc_connector *connector,
+grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
+                                        grpc_connector *connector,
                                         grpc_subchannel_args *args);
 
 #endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_H */
diff --git a/src/core/client_config/subchannel_index.c b/src/core/client_config/subchannel_index.c
index ffe6c1fe931..9f6ecca2959 100644
--- a/src/core/client_config/subchannel_index.c
+++ b/src/core/client_config/subchannel_index.c
@@ -31,49 +31,83 @@
  *
  */
 
+#include "src/core/client_config/subchannel_index.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/avl.h>
+#include <grpc/support/tls.h>
+
+#include "src/core/channel/channel_args.h"
+
 /* a map of subchannel_key --> subchannel, used for detecting connections
    to the same destination in order to share them */
 static gpr_avl g_subchannel_index;
 
 static gpr_mu g_mu;
 
-struct subchannel_key {
-  size_t addr_len;
-  struct sockaddr *addr;
-  grpc_channel_args *normalized_args;
+struct grpc_subchannel_key {
+	grpc_connector *connector;
+	grpc_subchannel_args args;
 };
 
 GPR_TLS_DECL(subchannel_index_exec_ctx);
 
-static subchannel_key *subchannel_key_create(struct sockaddr *sockaddr, size_t addr_len, grpc_channel_args *args) {
-  subchannel_key *k = gpr_malloc(sizeof(*k));
-  k->addr_len = addr_len;
-  k->addr = gpr_malloc(addr_len);
-  memcpy(k->addr, addr, addr_len);
-  k->normalized_args = grpc_channel_args_normalize(args);
-  return k;
+static void enter_ctx(grpc_exec_ctx *exec_ctx) {
+	GPR_ASSERT(gpr_tls_get(&subchannel_index_exec_ctx) == 0);
+	gpr_tls_set(&subchannel_index_exec_ctx, (intptr_t)exec_ctx);
+}
+
+static void leave_ctx(grpc_exec_ctx *exec_ctx) {
+	GPR_ASSERT(gpr_tls_get(&subchannel_index_exec_ctx) == (intptr_t)exec_ctx);
+	gpr_tls_set(&subchannel_index_exec_ctx, 0);
+}
+
+static grpc_exec_ctx *current_ctx() {
+	grpc_exec_ctx *c = (grpc_exec_ctx *)gpr_tls_get(&subchannel_index_exec_ctx);
+	GPR_ASSERT(c != NULL);
+	return c;
 }
 
-static subchannel_key *subchannel_key_copy(subchannel_key *k) {
-  subchannel_key *k = gpr_malloc(sizeof(*k));
-  k->addr_len = addr_len;
-  k->addr = gpr_malloc(addr_len);
-  memcpy(k->addr, addr, addr_len);
-  k->normalized_args = grpc_channel_args_copy(args);
+static grpc_subchannel_key *create_key(grpc_connector *connector, grpc_subchannel_args *args, grpc_channel_args *(*copy_channel_args)(const grpc_channel_args *args)) {
+  grpc_subchannel_key *k = gpr_malloc(sizeof(*k));
+  k->connector = grpc_connector_ref(connector);
+  k->args.filter_count = args->filter_count;
+  k->args.filters = gpr_malloc(sizeof(*k->args.filters) * k->args.filter_count);
+  memcpy(k->args.filters, args->filters, sizeof(*k->args.filters) * k->args.filter_count);
+  k->args.addr_len = args->addr_len;
+  k->args.addr = gpr_malloc(args->addr_len);
+  memcpy(k->args.addr, args->addr, k->args.addr_len);
+  k->args.args = copy_channel_args(args->args);
   return k;
 }
 
-static int subchannel_key_compare(subchannel_key *a, subchannel_key *b) {
-  int c = GPR_ICMP(a->addr_len, b->addr_len);
+grpc_subchannel_key *grpc_subchannel_key_create(grpc_connector *connector, grpc_subchannel_args *args) {
+	return create_key(connector, args, grpc_channel_args_normalize);
+}
+
+static grpc_subchannel_key *subchannel_key_copy(grpc_subchannel_key *k) {
+	return create_key(k->connector, &k->args, grpc_channel_args_copy);
+}
+
+static int subchannel_key_compare(grpc_subchannel_key *a, grpc_subchannel_key *b) {
+  int c = GPR_ICMP(a->connector, b->connector);
+  if (c != 0) return c;
+  c = GPR_ICMP(a->args.addr_len, b->args.addr_len);
   if (c != 0) return c;
-  c = memcmp(a->addr, b->addr, a->addr_len);
+  c = GPR_ICMP(a->args.filter_count, b->args.filter_count);
   if (c != 0) return c;
-  return grpc_channel_args_compare(a->normalized_args, b->normalized_args);
+  c = memcmp(a->args.addr, b->args.addr, a->args.addr_len);
+  if (c != 0) return c;
+  c = memcmp(a->args.filters, b->args.filters, a->args.filter_count * sizeof(*a->args.filters));
+  return grpc_channel_args_compare(a->args.args, b->args.args);
 }
 
-static void subchannel_key_destroy(subchannel_key *k) {
-  gpr_free(k->addr);
-  grpc_channel_args_destroy(k->normalized_args);
+static void subchannel_key_destroy(grpc_subchannel_key *k) {
+  gpr_free(k->args.addr);
+  gpr_free(k->args.filters);
+  grpc_channel_args_destroy((grpc_channel_args*)k->args.args);
   gpr_free(k);
 }
 
@@ -85,16 +119,17 @@ static void *sck_avl_copy(void *p) {
   return subchannel_key_copy(p);
 }
 
-static void *sck_avl_compare(void *a, void *b) {
+static long sck_avl_compare(void *a, void *b) {
   return subchannel_key_compare(a, b);
 }
 
 static void scv_avl_destroy(void *p) {
-  GRPC_SUBCHANNEL_UNREF(exec_ctx, p, "subchannel_index");
+	grpc_exec_ctx *exec_ctx = current_ctx();
+  GRPC_SUBCHANNEL_WEAK_UNREF(exec_ctx, p, "subchannel_index");
 }
 
 static void *scv_avl_copy(void *p) { 
-  GRPC_SUBCHANNEL_REF(p, "subchannel_index");
+  GRPC_SUBCHANNEL_WEAK_REF(p, "subchannel_index");
   return p; 
 }
 
@@ -107,26 +142,31 @@ static const gpr_avl_vtable subchannel_avl_vtable = {
 };
 
 grpc_subchannel *grpc_subchannel_index_find(
-		grpc_exec_ctx *ctx,
+		grpc_exec_ctx *exec_ctx,
 		grpc_connector *connector,
 		grpc_subchannel_args *args) {
+	enter_ctx(ctx);
+
 	gpr_mu_lock(&g_mu);
 	gpr_avl index = gpr_avl_ref(g_subchannel_index);
 	gpr_mu_unlock(&g_mu);
 
 	subchannel_key *key = subchannel_key_create(connector, args);
-	grpc_subchannel *c = grpc_subchannel_ref(gpr_avl_get(index, key));
+	grpc_subchannel *c = GRPC_SUBCHANNEL_REF_FROM_WEAK_REF(gpr_avl_get(index, key));
 	subchannel_key_destroy(key);
 	gpr_avl_unref(index);
 
+	leave_ctx(ctx);
 	return c;
 }
 
 grpc_subchannel *grpc_subchannel_index_register(
-	  grpc_exec_ctx *ctx,
+	  grpc_exec_ctx *exec_ctx,
 		grpc_connector *connector, 
 		grpc_subchannel_args *args, 
 		grpc_subchannel *constructed) {
+	enter_ctx(ctx);
+
 	subchannel_key *key = subchannel_key_create(connector, args);
 	grpc_subchannel *c = NULL;
 
@@ -137,7 +177,7 @@ grpc_subchannel *grpc_subchannel_index_register(
 
 		c = gpr_avl_get(index, key);
 		if (c != NULL) {
-			GRPC_SUBCHANNEL_UNREF(constructed);
+			GRPC_SUBCHANNEL_WEAK_UNREF(constructed);
 		} else {
 			gpr_avl updated = gpr_avl_add(index, key, constructed);
 
@@ -151,5 +191,7 @@ grpc_subchannel *grpc_subchannel_index_register(
 		gpr_avl_unref(index);
 	}
 
+	leave_ctx(ctx);
+
 	return c;
 }
diff --git a/src/core/client_config/subchannel_index.h b/src/core/client_config/subchannel_index.h
index d501e121f1d..dfbc3228d9c 100644
--- a/src/core/client_config/subchannel_index.h
+++ b/src/core/client_config/subchannel_index.h
@@ -34,6 +34,28 @@
 #ifndef GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
 #define GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H
 
+#include "src/core/client_config/connector.h"
+#include "src/core/client_config/subchannel.h"
 
+typedef struct grpc_subchannel_key grpc_subchannel_key;
+
+grpc_subchannel_key *grpc_subchannel_key_create(
+    grpc_connector *con, grpc_subchannel_args *args);
+
+void grpc_subchannel_key_destroy(grpc_subchannel_key *key);
+
+grpc_subchannel *grpc_subchannel_index_find(
+    grpc_exec_ctx *ctx,
+    grpc_subchannel_key *key);
+
+grpc_subchannel *grpc_subchannel_index_register(
+    grpc_exec_ctx *ctx,
+    grpc_subchannel_key *key, 
+    grpc_subchannel *constructed);
+
+void grpc_subchannel_index_unregister(
+    grpc_exec_ctx *ctx,
+    grpc_subchannel_key *key,
+    grpc_subchannel *constructed);
 
 #endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_SUBCHANNEL_INDEX_H */
diff --git a/src/core/surface/secure_channel_create.c b/src/core/surface/secure_channel_create.c
index 552a570713d..38f3e28e3da 100644
--- a/src/core/surface/secure_channel_create.c
+++ b/src/core/surface/secure_channel_create.c
@@ -238,7 +238,7 @@ static grpc_subchannel *subchannel_factory_create_subchannel(
   gpr_mu_init(&c->mu);
   gpr_ref_init(&c->refs, 1);
   args->args = final_args;
-  s = grpc_subchannel_create(&c->base, args);
+  s = grpc_subchannel_create(exec_ctx, &c->base, args);
   grpc_connector_unref(exec_ctx, &c->base);
   grpc_channel_args_destroy(final_args);
   return s;