diff --git a/src/qos/congestion_control.cpp b/src/qos/congestion_control.cpp
new file mode 100644
index 0000000..060b616
--- /dev/null
+++ b/src/qos/congestion_control.cpp
@@ -0,0 +1,5 @@
+#include "congestion_control.h"
+
+CongestionControl::CongestionControl() {}
+
+CongestionControl::~CongestionControl() {}
\ No newline at end of file
diff --git a/src/qos/congestion_control.h b/src/qos/congestion_control.h
new file mode 100644
index 0000000..babe027
--- /dev/null
+++ b/src/qos/congestion_control.h
@@ -0,0 +1,12 @@
+#ifndef _CONGESTION_CONTROL_H_
+#define _CONGESTION_CONTROL_H_
+
+class CongestionControl {
+ public:
+  CongestionControl();
+  ~CongestionControl();
+
+ private:
+};
+
+#endif
\ No newline at end of file
diff --git a/src/ice/ice_transmission.cpp b/src/transmission/ice_transmission.cpp
similarity index 98%
rename from src/ice/ice_transmission.cpp
rename to src/transmission/ice_transmission.cpp
index 296d03a..829da88 100644
--- a/src/ice/ice_transmission.cpp
+++ b/src/transmission/ice_transmission.cpp
@@ -80,7 +80,7 @@ int IceTransmission::InitIceTransmission(std::string &ip, int port) {
 }
 
 int IceTransmission::DestroyIceTransmission() {
-  LOG_INFO("[{}] Destroy ice transmission", user_id_);
+  LOG_INFO("[{}->{}] Destroy ice transmission", user_id_, remote_user_id_);
   return ice_agent_->DestoryIceAgent();
 }
 
diff --git a/src/ice/ice_transmission.h b/src/transmission/ice_transmission.h
similarity index 95%
rename from src/ice/ice_transmission.h
rename to src/transmission/ice_transmission.h
index c087337..7d86a62 100644
--- a/src/ice/ice_transmission.h
+++ b/src/transmission/ice_transmission.h
@@ -3,6 +3,7 @@
 
 #include <iostream>
 
+#include "congestion_control.h"
 #include "ice_agent.h"
 #include "ws_transmission.h"
 
@@ -56,6 +57,7 @@ class IceTransmission {
  private:
   IceAgent *ice_agent_ = nullptr;
   WsTransmission *ice_ws_transport_ = nullptr;
+  CongestionControl *congestion_control_ = nullptr;
   std::function<void(const char *, size_t)> on_receive_ice_msg_cb_ = nullptr;
   std::string local_sdp_;
   std::string remote_sdp_;
diff --git a/xmake.lua b/xmake.lua
index 18d369a..3cc83bc 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -46,7 +46,7 @@ target("ice")
     add_deps("log", "common", "ws")
     add_packages("asio", "nlohmann_json", "libjuice")
     add_files("src/ice/*.cpp")
-    add_includedirs("src/ws")
+    add_includedirs("src/ws", {public = true})
     add_includedirs("thirdparty/libjuice/include", {public = true})
 
 target("ws")
@@ -56,21 +56,33 @@ target("ws")
     add_packages("asio")
     add_includedirs("thirdparty/websocketpp/include", {public = true})
 
+target("qos")
+    set_kind("static")
+    add_deps("log")
+    add_files("src/qos/*.cpp")
+
+target("transmission")
+    set_kind("static")
+    add_deps("log", "ws", "ice", "qos")
+    add_files("src/transmission/*.cpp")
+    add_packages("asio", "nlohmann_json")
+    add_includedirs("src/ws", "src/ice", "src/qos", {public = true})
+
 target("pc")
     set_kind("static")
     add_deps("log")
-    add_deps("ws", "ice", "inih", "common")
+    add_deps("ws", "ice", "transmission", "inih", "common")
     add_files("src/pc/*.cpp")
     add_packages("asio", "nlohmann_json")
-    add_includedirs("src/ws", "src/ice")
+    add_includedirs("src/transmission", {public = true})
 
 target("projectx")
     set_kind("shared")
     add_deps("log")
-    add_deps("ice", "ws", "pc")
+    add_deps("pc")
     add_files("src/rtc/*.cpp")
     add_packages("asio", "nlohmann_json")
-    add_includedirs("src/rtc", "src/ice", "src/ws", "src/pc", "src/interface")
+    add_includedirs("src/rtc", "src/pc", "src/interface")
     add_rules("utils.symbols.export_all", {export_classes = true})
     -- set_policy("build.merge_archive", true)
     -- set_targetdir("$(projectdir)/libdrtc/lib")