概述

音视频通信时为了节省服务器带宽，通信效率最好的就是p2p，但是在现实的应用场景中，我们的客户端都是在大局域网内部的，stun协议就是要解决如何穿透这些局域网实现p2p。

metaRTC5.0最新版本支持stun，使p2p在互联网上利用网络穿透技术实现通信。

下载源码

https://github.com/metartc/metaRTC/releases/tag/5.0.022https://github.com/metartc/metaRTC/releases/tag/5.0.022 https://gitee.com/metartc/metaRTC/releases/5.0.022https://gitee.com/metartc/metaRTC/releases/5.0.022

?metaRTC5.0编程

metaRTC5.0 p2p stun编程有两种模式：

websockt+stun
http+frpc(ngrok)+stun

配置参数

代码配置参数

 strcpy(m_context->avinfo.rtc.iceServerIP,"182.92.163.143"); //stun服务器地址
 m_context->avinfo.rtc.iceStunPort=3478; //stun服务器端口
 m_context->avinfo.rtc.hasIceServer=1; //1:启用stun 0:关闭stun

或者在配置文件yang_config.ini中配置

[rtc]
hasIceServer=1
usingDatachannel=1
iceStunPort=3478
iceServerIP=182.92.163.143
audioQueueCount=5
vidoeQueueCount=5

模式一(websockt+stun)

代码在libmetartc5/src/yangp2p/YangP2pRtcIce.cpp中

//发起连接到对端
int32_t YangP2pRtcIce::connectPeer(int32_t nettype, string server,int32_t localPort,int32_t pport,string app,string stream) {
	int32_t ret = 0;
	YangPeerConnection* sh=(YangPeerConnection*)calloc(sizeof(YangPeerConnection),1);
    ....配置参数.....
    //初始化YangPeerConnection
	yang_create_peerConnection(sh);
    sh->init(&sh->peer);

	char* localSdp; //本端sdp
	char* remoteSdp=(char*)calloc(12*1000,1); //对端sdp
	//向stun服务器发送stun request取得外网地址和端口
	if(m_context->avinfo.rtc.hasIceServer){
		if(sh->requestStunServer(&sh->peer)!=Yang_Ok) yang_error("request stun server fail!");
	}
    //取得本端sdp
	sh->createOffer(&sh->peer, &localSdp);
	
    将sdp通过信令服务传输到对端
	

	//取得对端sdp后，启动metartc
	ret=sh->setRemoteDescription(&sh->peer,remoteSdp);
}

//取得对端sdp后， 调用sh->createAnswer(&sh->peer,answer);
//取得answer后，通过信令服务传会对端
int32_t YangP2pRtcIce::addPeer(char* remotesdp,char* answer,char* remoteIp,int32_t localPort,int* phasplay) {
   配置参数...
   //初始化YangPeerConnection
	yang_create_peerConnection(sh);
    sh->init(&sh->peer);

	//向stun服务器发送stun request取得外网地址和端口
	if(m_context->avinfo.rtc.hasIceServer){
		if(sh->requestStunServer(&sh->peer)!=Yang_Ok) yang_error("request stun server fail!");
	}
   //取得answer Sdp
	ret = sh->createAnswer(&sh->peer,answer);
    ....取得answer后，通过信令服务传会对端

	//取得对端sdp后，启动metartc
	ret = sh->setRemoteDescription(&sh->peer,remotesdp);

	.....
}