diff --git a/src/Common/strCoding.cpp b/src/Common/strCoding.cpp
index 90fc7096..59a0b7e4 100644
--- a/src/Common/strCoding.cpp
+++ b/src/Common/strCoding.cpp
@@ -79,7 +79,7 @@ string strCoding::UrlEncodePath(const string &str) {
             out.push_back(ch);
         } else {
             char buf[4];
-            sprintf(buf, "%%%X%X", (uint8_t) ch >> 4, (uint8_t) ch & 0x0F);
+            snprintf(buf, 4, "%%%X%X", (uint8_t) ch >> 4, (uint8_t) ch & 0x0F);
             out.append(buf);
         }
     }
@@ -96,7 +96,7 @@ string strCoding::UrlEncodeComponent(const string &str) {
             out.push_back(ch);
         } else {
             char buf[4];
-            sprintf(buf, "%%%X%X", (uint8_t) ch >> 4, (uint8_t) ch & 0x0F);
+            snprintf(buf, 4, "%%%X%X", (uint8_t) ch >> 4, (uint8_t) ch & 0x0F);
             out.append(buf);
         }
     }
diff --git a/srt/SrtSession.cpp b/srt/SrtSession.cpp
index 5211fd4c..8a671c96 100644
--- a/srt/SrtSession.cpp
+++ b/srt/SrtSession.cpp
@@ -16,41 +16,17 @@ SrtSession::SrtSession(const Socket::Ptr &sock)
     // TraceL<<"after addr len "<<addr_len<<" family "<<_peer_addr.ss_family;
 }
 
-EventPoller::Ptr SrtSession::queryPoller(const Buffer::Ptr &buffer) {
-    uint8_t *data = (uint8_t *)buffer->data();
-    size_t size = buffer->size();
-
-    if (DataPacket::isDataPacket(data, size)) {
-        uint32_t socket_id = DataPacket::getSocketID(data, size);
-        auto trans = SrtTransportManager::Instance().getItem(std::to_string(socket_id));
-        return trans ? trans->getPoller() : nullptr;
-    }
-
-    if (HandshakePacket::isHandshakePacket(data, size)) {
-        auto type = HandshakePacket::getHandshakeType(data, size);
-        if (type == HandshakePacket::HS_TYPE_INDUCTION) {
-            // 握手第一阶段
-            return nullptr;
-        } else if (type == HandshakePacket::HS_TYPE_CONCLUSION) {
-            // 握手第二阶段
-            uint32_t sync_cookie = HandshakePacket::getSynCookie(data, size);
-            auto trans = SrtTransportManager::Instance().getHandshakeItem(std::to_string(sync_cookie));
-            return trans ? trans->getPoller() : nullptr;
-        } else {
-            WarnL << " not reach there";
-        }
-    } else {
-        uint32_t socket_id = ControlPacket::getSocketID(data, size);
-        auto trans = SrtTransportManager::Instance().getItem(std::to_string(socket_id));
-        return trans ? trans->getPoller() : nullptr;
-    }
-    return nullptr;
-}
-
 void SrtSession::attachServer(const toolkit::Server &server) {
     SockUtil::setRecvBuf(getSock()->rawFD(), 1024 * 1024);
 }
 
+extern SrtTransport::Ptr querySrtTransport(uint8_t *data, size_t size, const EventPoller::Ptr& poller);
+
+EventPoller::Ptr SrtSession::queryPoller(const Buffer::Ptr &buffer) {
+    auto transport = querySrtTransport((uint8_t *)buffer->data(), buffer->size(), nullptr);
+    return transport ? transport->getPoller() : nullptr;
+}
+
 void SrtSession::onRecv(const Buffer::Ptr &buffer) {
     uint8_t *data = (uint8_t *)buffer->data();
     size_t size = buffer->size();
@@ -58,45 +34,7 @@ void SrtSession::onRecv(const Buffer::Ptr &buffer) {
     if (_find_transport) {
         //只允许寻找一次transport
         _find_transport = false;
-
-        if (DataPacket::isDataPacket(data, size)) {
-            uint32_t socket_id = DataPacket::getSocketID(data, size);
-            auto trans = SrtTransportManager::Instance().getItem(std::to_string(socket_id));
-            if (trans) {
-                _transport = std::move(trans);
-            } else {
-                WarnL << " data packet not find transport ";
-            }
-        }
-
-        if (HandshakePacket::isHandshakePacket(data, size)) {
-            auto type = HandshakePacket::getHandshakeType(data, size);
-            if (type == HandshakePacket::HS_TYPE_INDUCTION) {
-                // 握手第一阶段
-                _transport = std::make_shared<SrtTransportImp>(getPoller());
-
-            } else if (type == HandshakePacket::HS_TYPE_CONCLUSION) {
-                // 握手第二阶段
-                uint32_t sync_cookie = HandshakePacket::getSynCookie(data, size);
-                auto trans = SrtTransportManager::Instance().getHandshakeItem(std::to_string(sync_cookie));
-                if (trans) {
-                    _transport = std::move(trans);
-                } else {
-                    WarnL << " hanshake packet not find transport ";
-                }
-            } else {
-                WarnL << " not reach there";
-            }
-        } else {
-            uint32_t socket_id = ControlPacket::getSocketID(data, size);
-            auto trans = SrtTransportManager::Instance().getItem(std::to_string(socket_id));
-            if (trans) {
-                _transport = std::move(trans);
-            } else {
-                WarnL << " not find transport";
-            }
-        }
-
+        _transport = querySrtTransport(data, size, getPoller());
         if (_transport) {
             _transport->setSession(static_pointer_cast<Session>(shared_from_this()));
         }
diff --git a/srt/SrtTransport.cpp b/srt/SrtTransport.cpp
index 7388f3a0..f88cf428 100644
--- a/srt/SrtTransport.cpp
+++ b/srt/SrtTransport.cpp
@@ -61,7 +61,7 @@ void SrtTransport::switchToOtherTransport(uint8_t *buf, int len, uint32_t socket
     BufferRaw::Ptr tmp = BufferRaw::create();
     struct sockaddr_storage tmp_addr = *addr;
     tmp->assign((char *)buf, len);
-    auto trans = SrtTransportManager::Instance().getItem(std::to_string(socketid));
+    auto trans = SrtTransportManager::Instance().getItem(socketid);
     if (trans) {
         trans->getPoller()->async([tmp, tmp_addr, trans] {
             trans->inputSockData((uint8_t *)tmp->data(), tmp->size(), (struct sockaddr_storage *)&tmp_addr);
@@ -700,30 +700,30 @@ void SrtTransport::sendPacket(Buffer::Ptr pkt, bool flush) {
     }
 }
 
-std::string SrtTransport::getIdentifier() {
+std::string SrtTransport::getIdentifier() const {
     return _selected_session ? _selected_session->getIdentifier() : "";
 }
 
 void SrtTransport::registerSelfHandshake() {
-    SrtTransportManager::Instance().addHandshakeItem(std::to_string(_sync_cookie), shared_from_this());
+    SrtTransportManager::Instance().addHandshakeItem(_sync_cookie, shared_from_this());
 }
 
 void SrtTransport::unregisterSelfHandshake() {
     if (_sync_cookie == 0) {
         return;
     }
-    SrtTransportManager::Instance().removeHandshakeItem(std::to_string(_sync_cookie));
+    SrtTransportManager::Instance().removeHandshakeItem(_sync_cookie);
 }
 
 void SrtTransport::registerSelf() {
     if (_socket_id == 0) {
         return;
     }
-    SrtTransportManager::Instance().addItem(std::to_string(_socket_id), shared_from_this());
+    SrtTransportManager::Instance().addItem(_socket_id, shared_from_this());
 }
 
 void SrtTransport::unregisterSelf() {
-    SrtTransportManager::Instance().removeItem(std::to_string(_socket_id));
+    SrtTransportManager::Instance().removeItem(_socket_id);
 }
 
 void SrtTransport::onShutdown(const SockException &ex) {
@@ -739,7 +739,7 @@ void SrtTransport::onShutdown(const SockException &ex) {
     }
 }
 
-size_t SrtTransport::getPayloadSize() {
+size_t SrtTransport::getPayloadSize() const {
     size_t ret = (_mtu - 28 - 16) / 188 * 188;
     return ret;
 }
@@ -792,15 +792,13 @@ SrtTransportManager &SrtTransportManager::Instance() {
     return s_instance;
 }
 
-void SrtTransportManager::addItem(const std::string &key, const SrtTransport::Ptr &ptr) {
+void SrtTransportManager::addItem(const uint32_t key, const SrtTransport::Ptr &ptr) {
     std::lock_guard<std::mutex> lck(_mtx);
     _map[key] = ptr;
 }
 
-SrtTransport::Ptr SrtTransportManager::getItem(const std::string &key) {
-    if (key.empty()) {
-        return nullptr;
-    }
+SrtTransport::Ptr SrtTransportManager::getItem(const uint32_t key) {
+    assert(key > 0);
     std::lock_guard<std::mutex> lck(_mtx);
     auto it = _map.find(key);
     if (it == _map.end()) {
@@ -809,25 +807,23 @@ SrtTransport::Ptr SrtTransportManager::getItem(const std::string &key) {
     return it->second.lock();
 }
 
-void SrtTransportManager::removeItem(const std::string &key) {
+void SrtTransportManager::removeItem(const uint32_t key) {
     std::lock_guard<std::mutex> lck(_mtx);
     _map.erase(key);
 }
 
-void SrtTransportManager::addHandshakeItem(const std::string &key, const SrtTransport::Ptr &ptr) {
+void SrtTransportManager::addHandshakeItem(const uint32_t key, const SrtTransport::Ptr &ptr) {
     std::lock_guard<std::mutex> lck(_handshake_mtx);
     _handshake_map[key] = ptr;
 }
 
-void SrtTransportManager::removeHandshakeItem(const std::string &key) {
+void SrtTransportManager::removeHandshakeItem(const uint32_t key) {
     std::lock_guard<std::mutex> lck(_handshake_mtx);
     _handshake_map.erase(key);
 }
 
-SrtTransport::Ptr SrtTransportManager::getHandshakeItem(const std::string &key) {
-    if (key.empty()) {
-        return nullptr;
-    }
+SrtTransport::Ptr SrtTransportManager::getHandshakeItem(const uint32_t key) {
+    assert(key > 0);
     std::lock_guard<std::mutex> lck(_handshake_mtx);
     auto it = _handshake_map.find(key);
     if (it == _handshake_map.end()) {
diff --git a/srt/SrtTransport.hpp b/srt/SrtTransport.hpp
index fe3dfe69..56b75b4c 100644
--- a/srt/SrtTransport.hpp
+++ b/srt/SrtTransport.hpp
@@ -45,7 +45,7 @@ public:
     virtual void inputSockData(uint8_t *buf, int len, struct sockaddr_storage *addr);
     virtual void onSendTSData(const Buffer::Ptr &buffer, bool flush);
 
-    std::string getIdentifier();
+    std::string getIdentifier() const;
     void unregisterSelf();
     void unregisterSelfHandshake();
 
@@ -89,7 +89,7 @@ private:
     void sendShutDown();
     void sendMsgDropReq(uint32_t first, uint32_t last);
 
-    size_t getPayloadSize();
+    size_t getPayloadSize() const;
 
     void createTimerForCheckAlive();
 
@@ -164,23 +164,23 @@ private:
 class SrtTransportManager {
 public:
     static SrtTransportManager &Instance();
-    SrtTransport::Ptr getItem(const std::string &key);
-    void addItem(const std::string &key, const SrtTransport::Ptr &ptr);
-    void removeItem(const std::string &key);
+    SrtTransport::Ptr getItem(const uint32_t key);
+    void addItem(const uint32_t key, const SrtTransport::Ptr &ptr);
+    void removeItem(const uint32_t key);
 
-    void addHandshakeItem(const std::string &key, const SrtTransport::Ptr &ptr);
-    void removeHandshakeItem(const std::string &key);
-    SrtTransport::Ptr getHandshakeItem(const std::string &key);
+    void addHandshakeItem(const uint32_t key, const SrtTransport::Ptr &ptr);
+    void removeHandshakeItem(const uint32_t key);
+    SrtTransport::Ptr getHandshakeItem(const uint32_t key);
 
 private:
     SrtTransportManager() = default;
 
 private:
     std::mutex _mtx;
-    std::unordered_map<std::string, std::weak_ptr<SrtTransport>> _map;
+    std::unordered_map<uint32_t , std::weak_ptr<SrtTransport>> _map;
 
     std::mutex _handshake_mtx;
-    std::unordered_map<std::string, std::weak_ptr<SrtTransport>> _handshake_map;
+    std::unordered_map<uint32_t, std::weak_ptr<SrtTransport>> _handshake_map;
 };
 
 } // namespace SRT
diff --git a/srt/SrtTransportImp.cpp b/srt/SrtTransportImp.cpp
index 087bb4ae..8f818655 100644
--- a/srt/SrtTransportImp.cpp
+++ b/srt/SrtTransportImp.cpp
@@ -24,6 +24,32 @@ SrtTransportImp::~SrtTransportImp() {
     }
 }
 
+
+SrtTransport::Ptr querySrtTransport(uint8_t *data, size_t size, const EventPoller::Ptr& poller) {
+    if (DataPacket::isDataPacket(data, size)) {
+        uint32_t socket_id = DataPacket::getSocketID(data, size);
+        return SrtTransportManager::Instance().getItem(socket_id);
+    }
+
+    if (HandshakePacket::isHandshakePacket(data, size)) {
+        auto type = HandshakePacket::getHandshakeType(data, size);
+        if (type == HandshakePacket::HS_TYPE_INDUCTION) {
+            // 握手第一阶段
+            return poller ? std::make_shared<SrtTransportImp>(poller) : nullptr;
+        }
+
+        if (type == HandshakePacket::HS_TYPE_CONCLUSION) {
+            // 握手第二阶段
+            uint32_t sync_cookie = HandshakePacket::getSynCookie(data, size);
+            return SrtTransportManager::Instance().getHandshakeItem(sync_cookie);
+        }
+    }
+
+    uint32_t socket_id = ControlPacket::getSocketID(data, size);
+    return SrtTransportManager::Instance().getItem(socket_id);
+}
+
+
 void SrtTransportImp::onHandShakeFinished(std::string &streamid, struct sockaddr_storage *addr) {
     SrtTransport::onHandShakeFinished(streamid,addr);
     // TODO parse stream id like this zlmediakit.com/live/test?token=1213444&type=push