diff --git a/BUILD b/BUILD
index 1ba6e68a..2caeb712 100644
--- a/BUILD
+++ b/BUILD
@@ -80,6 +80,7 @@ proto_library(
         "//contrib/envoy/extensions/filters/network/postgres_proxy/v3alpha:pkg",
         "//contrib/envoy/extensions/filters/network/rocketmq_proxy/v3:pkg",
         "//contrib/envoy/extensions/filters/network/sip_proxy/router/v3alpha:pkg",
+        "//contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha:pkg",
         "//contrib/envoy/extensions/filters/network/sip_proxy/v3alpha:pkg",
         "//contrib/envoy/extensions/private_key_providers/cryptomb/v3alpha:pkg",
         "//contrib/envoy/extensions/vcl/v3alpha:pkg",
diff --git a/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/BUILD b/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/BUILD
new file mode 100644
index 00000000..7753cfeb
--- /dev/null
+++ b/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/BUILD
@@ -0,0 +1,13 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    has_services = True,
+    deps = [
+        "//envoy/config/core/v3:pkg",
+        "@com_github_cncf_udpa//udpa/annotations:pkg",
+    ],
+)
diff --git a/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/tra.proto b/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/tra.proto
new file mode 100644
index 00000000..ca6baf9f
--- /dev/null
+++ b/contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/tra.proto
@@ -0,0 +1,126 @@
+syntax = "proto3";
+
+package envoy.extensions.filters.network.sip_proxy.tra.v3alpha;
+
+import "envoy/config/core/v3/config_source.proto";
+import "envoy/config/core/v3/grpc_service.proto";
+
+import "google/protobuf/duration.proto";
+
+import "udpa/annotations/status.proto";
+import "udpa/annotations/versioning.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.filters.network.sip_proxy.tra.v3alpha";
+option java_outer_classname = "TraProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/sip_proxy/tra/v3alpha";
+option java_generic_services = true;
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: TrafficRoutingAssistant]
+
+service TraService {
+  rpc Create(TraServiceRequest) returns (TraServiceResponse) {
+  }
+
+  rpc Update(TraServiceRequest) returns (TraServiceResponse) {
+  }
+
+  rpc Retrieve(TraServiceRequest) returns (TraServiceResponse) {
+  }
+
+  rpc Delete(TraServiceRequest) returns (TraServiceResponse) {
+  }
+
+  rpc Subscribe(TraServiceRequest) returns (stream TraServiceResponse) {
+  }
+}
+
+message TraServiceConfig {
+  // Specifies the gRPC service that hosts the rate limit service. The client
+  // will connect to this cluster when it needs to make rate limit service
+  // requests.
+  config.core.v3.GrpcService grpc_service = 1 [(validate.rules).message = {required: true}];
+
+  // API version for rate limit transport protocol. This describes the rate limit gRPC endpoint and
+  // version of messages used on the wire.
+  config.core.v3.ApiVersion transport_api_version = 2
+      [(validate.rules).enum = {defined_only: true}];
+
+  google.protobuf.Duration timeout = 3;
+}
+
+// [#next-free-field: 7]
+message TraServiceRequest {
+  string type = 1;
+
+  oneof request {
+    CreateRequest create_request = 2;
+
+    UpdateRequest update_request = 3;
+
+    RetrieveRequest retrieve_request = 4;
+
+    DeleteRequest delete_request = 5;
+
+    SubscribeRequest subscribe_request = 6;
+  }
+}
+
+// [#next-free-field: 9]
+message TraServiceResponse {
+  string type = 1;
+
+  int32 ret = 2;
+
+  string reason = 3;
+
+  oneof response {
+    CreateResponse create_response = 4;
+
+    UpdateResponse update_response = 5;
+
+    RetrieveResponse retrieve_response = 6;
+
+    DeleteResponse delete_response = 7;
+
+    SubscribeResponse subscribe_response = 8;
+  }
+}
+
+message CreateRequest {
+  map<string, string> data = 1;
+}
+
+message CreateResponse {
+}
+
+message UpdateRequest {
+  map<string, string> data = 1;
+}
+
+message UpdateResponse {
+}
+
+message RetrieveRequest {
+  string key = 1;
+}
+
+message RetrieveResponse {
+  map<string, string> data = 1;
+}
+
+message DeleteRequest {
+  string key = 1;
+}
+
+message DeleteResponse {
+}
+
+message SubscribeRequest {
+}
+
+message SubscribeResponse {
+  map<string, string> data = 1;
+}
diff --git a/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/BUILD b/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/BUILD
index ee92fb65..808cd297 100644
--- a/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/BUILD
+++ b/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/BUILD
@@ -5,5 +5,8 @@ load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
 licenses(["notice"])  # Apache 2
 
 api_proto_package(
-    deps = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+    deps = [
+        "//contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha:pkg",
+        "@com_github_cncf_udpa//udpa/annotations:pkg",
+    ],
 )
diff --git a/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/sip_proxy.proto b/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/sip_proxy.proto
index 5347eb77..d13c2cde 100644
--- a/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/sip_proxy.proto
+++ b/contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/sip_proxy.proto
@@ -2,6 +2,7 @@ syntax = "proto3";
 
 package envoy.extensions.filters.network.sip_proxy.v3alpha;
 
+import "contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha/tra.proto";
 import "contrib/envoy/extensions/filters/network/sip_proxy/v3alpha/route.proto";
 
 import "google/protobuf/any.proto";
@@ -65,6 +66,8 @@ message SipProxy {
 
     // points to domain match with own_domain
     string domain_match_parameter_name = 3;
+
+    tra.v3alpha.TraServiceConfig tra_service_config = 4;
   }
 
   // The human readable prefix to use when emitting statistics.
@@ -106,4 +109,16 @@ message SipProtocolOptions {
 
   // The Register with Authorization header should go to the same endpoint which send out the 401 Unauthorized.
   bool registration_affinity = 2;
+
+  // Customized affinity
+  repeated CustomizedAffinity customized_affinity = 3;
+}
+
+// For affinity
+message CustomizedAffinity {
+  string key_name = 1;
+
+  bool query = 2;
+
+  bool subscribe = 3;
 }
diff --git a/versioning/BUILD b/versioning/BUILD
index b2bba15b..33971396 100644
--- a/versioning/BUILD
+++ b/versioning/BUILD
@@ -17,6 +17,7 @@ proto_library(
         "//contrib/envoy/extensions/filters/network/postgres_proxy/v3alpha:pkg",
         "//contrib/envoy/extensions/filters/network/rocketmq_proxy/v3:pkg",
         "//contrib/envoy/extensions/filters/network/sip_proxy/router/v3alpha:pkg",
+        "//contrib/envoy/extensions/filters/network/sip_proxy/tra/v3alpha:pkg",
         "//contrib/envoy/extensions/filters/network/sip_proxy/v3alpha:pkg",
         "//contrib/envoy/extensions/private_key_providers/cryptomb/v3alpha:pkg",
         "//contrib/envoy/extensions/vcl/v3alpha:pkg",