diff --git a/webrtc/WebRtcTransport.cpp b/webrtc/WebRtcTransport.cpp
index 50acad51..6a7865c8 100644
--- a/webrtc/WebRtcTransport.cpp
+++ b/webrtc/WebRtcTransport.cpp
@@ -188,6 +188,7 @@ std::string WebRtcTransport::getAnswerSdp(const string &offer){
         _offer_sdp->loadFrom(offer);
         _offer_sdp->checkSdp();
         _offer_sdp->checkValidSSRC();
+        // onCheckSdp(SdpType::offer, *_offer_sdp);
         setRemoteDtlsFingerprint(*_offer_sdp);
 
         //// sdp 配置 ////
@@ -202,7 +203,7 @@ std::string WebRtcTransport::getAnswerSdp(const string &offer){
         //// 生成answer sdp ////
         _answer_sdp = configure.createAnswer(*_offer_sdp);
         _answer_sdp->checkSdp();
-        onCheckAnswer(*_answer_sdp);
+        onCheckSdp(SdpType::answer, *_answer_sdp);
         return _answer_sdp->toString();
     } catch (exception &ex) {
         onShutdown(SockException(Err_shutdown, ex.what()));
@@ -549,6 +550,17 @@ void WebRtcTransportImp::onCheckAnswer(RtcSession &sdp) {
     }
 }
 
+void WebRtcTransportImp::onCheckSdp(SdpType type, RtcSession &sdp) {
+    switch (type) {
+    case SdpType::answer:
+        onCheckAnswer(sdp);
+        break;
+    default:
+        // TODO for offer and other
+        break;
+    }
+}
+
 void WebRtcTransportImp::onRtcConfigure(RtcConfigure &configure) const {
     WebRtcTransport::onRtcConfigure(configure);
 
diff --git a/webrtc/WebRtcTransport.h b/webrtc/WebRtcTransport.h
index 081ff196..2ce8866b 100644
--- a/webrtc/WebRtcTransport.h
+++ b/webrtc/WebRtcTransport.h
@@ -106,7 +106,7 @@ protected:
 protected:
     virtual void onStartWebRTC() = 0;
     virtual void onRtcConfigure(RtcConfigure &configure) const;
-    virtual void onCheckAnswer(RtcSession &sdp) = 0;
+    virtual void onCheckSdp(SdpType type, RtcSession &sdp) = 0;
     virtual void onSendSockData(const char *buf, size_t len, struct sockaddr_in *dst, bool flush = true) = 0;
 
     virtual void onRtp(const char *buf, size_t len, uint64_t stamp_ms) = 0;
@@ -184,7 +184,7 @@ public:
 protected:
     void onStartWebRTC() override;
     void onSendSockData(const char *buf, size_t len, struct sockaddr_in *dst, bool flush = true) override;
-    void onCheckAnswer(RtcSession &sdp) override;
+    void onCheckSdp(SdpType type, RtcSession &sdp) override;
     void onRtcConfigure(RtcConfigure &configure) const override;
 
     void onRtp(const char *buf, size_t len, uint64_t stamp_ms) override;
@@ -222,6 +222,7 @@ private:
     void registerSelf();
     void unregisterSelf();
     void unrefSelf();
+    void onCheckAnswer(RtcSession &sdp);
 
 private:
     bool _simulcast = false;