端口号或范围在WebRTC SDP中的什么位置？

Question

在一个WebRTC客户端上，我有：

{
  "type": "offer",
  "offer": {
    "type": "offer",
    "sdp": "v=0\r\no=- 4017428944405878889 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0\r\na=msid-semantic: WMS\r\nm=application 9 UDP/TLS/RTP/SAVPF 118\r\nc=IN IP4 0.0.0.0\r\nb=AS:30\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:mtfU\r\na=ice-pwd:BaCDfuvP4mkox0Sqy6llUmDj\r\na=ice-options:trickle\r\na=fingerprint:sha-256 7B:98:25:53:99:2A:12:B6:CE:9C:C6:4C:2B:43:70:EF:83:32:65:AA:73:16:18:DA:89:E6:F6:23:56:68:27:88\r\na=setup:actpass\r\na=mid:0\r\na=sendrecv\r\na=msid:myDataChannel myDataChannel\r\na=rtcp-mux\r\na=rtpmap:118 google-data/90000\r\na=ssrc:1182245517 cname:BHhEtKMy+DBafeQn\r\na=ssrc:1182245517 msid:myDataChannel myDataChannel\r\na=ssrc:1182245517 mslabel:myDataChannel\r\na=ssrc:1182245517 label:myDataChannel\r\n"
  },
  "name": "test2"
}

{
  "type": "candidate",
  "candidate": {
    "candidate": "candidate:733638273 1 udp 2113937151 d8e8c8cc-a451-4eba-8251-3ac08c3548b6.local 34965 typ host generation 0 ufrag mtfU network-cost 999",
    "sdpMid": "0",
    "sdpMLineIndex": 0
  }
}

{"type":"answer","answer":{"type":"answer","sdp":"v=0\r\no=- 4017428944405878889 3 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0\r\na=msid-semantic: WMS\r\nm=application 9 UDP/TLS/RTP/SAVPF 118\r\nc=IN IP4 0.0.0.0\r\nb=AS:30\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=candidate:733638273 1 udp 2113937151 d8e8c8cc-a451-4eba-8251-3ac08c3548b6.local 34965 typ host generation 0 network-cost 999\r\na=ice-ufrag:mtfU\r\na=ice-pwd:BaCDfuvP4mkox0Sqy6llUmDj\r\na=ice-options:trickle\r\na=fingerprint:sha-256 7B:98:25:53:99:2A:12:B6:CE:9C:C6:4C:2B:43:70:EF:83:32:65:AA:73:16:18:DA:89:E6:F6:23:56:68:27:88\r\na=setup:passive\r\na=mid:0\r\na=sendrecv\r\na=msid:myDataChannel myDataChannel\r\na=rtcp-mux\r\na=rtpmap:118 google-data/90000\r\na=ssrc:1182245517 cname:BHhEtKMy+DBafeQn\r\n"}}

而另一个同级：

{
  "type": "answer",
  "answer": {
    "type": "answer",
    "sdp": "v=0\r\no=- 7982065255825887936 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0\r\na=msid-semantic: WMS\r\nm=application 9 UDP/TLS/RTP/SAVPF 118\r\nc=IN IP4 0.0.0.0\r\nb=AS:30\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:2O1J\r\na=ice-pwd:AjKk99fLkZUGgtFV+Eesuxbe\r\na=ice-options:trickle\r\na=fingerprint:sha-256 10:45:8E:24:4C:99:F2:5D:1F:FD:56:59:43:BF:25:B8:AA:76:AD:79:87:C6:56:86:DF:C4:CD:00:2C:F5:89:76\r\na=setup:active\r\na=mid:0\r\na=sendrecv\r\na=msid:myDataChannel myDataChannel\r\na=rtcp-mux\r\na=rtpmap:118 google-data/90000\r\na=ssrc:4167028587 cname:epC7SLhj7YgMHMB/\r\n"
  }
}


{
  "type": "candidate",
  "candidate": {
    "candidate": "candidate:733638273 1 udp 2113937151 13442325-85fc-4750-a0ed-1235f0b61bee.local 49233 typ host generation 0 ufrag 2O1J network-cost 999",
    "sdpMid": "0",
    "sdpMLineIndex": 0
  }
}

{
  "type": "offer",
  "offer": {
    "type": "offer",
    "sdp": "v=0\r\no=- 7982065255825887936 3 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE 0\r\na=msid-semantic: WMS\r\nm=application 9 UDP/TLS/RTP/SAVPF 118\r\nc=IN IP4 0.0.0.0\r\nb=AS:30\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=candidate:733638273 1 udp 2113937151 13442325-85fc-4750-a0ed-1235f0b61bee.local 49233 typ host generation 0 network-cost 999\r\na=ice-ufrag:2O1J\r\na=ice-pwd:AjKk99fLkZUGgtFV+Eesuxbe\r\na=ice-options:trickle\r\na=fingerprint:sha-256 10:45:8E:24:4C:99:F2:5D:1F:FD:56:59:43:BF:25:B8:AA:76:AD:79:87:C6:56:86:DF:C4:CD:00:2C:F5:89:76\r\na=setup:actpass\r\na=mid:0\r\na=sendrecv\r\na=msid:myDataChannel myDataChannel\r\na=rtcp-mux\r\na=rtpmap:118 google-data/90000\r\na=ssrc:4167028587 cname:epC7SLhj7YgMHMB/\r\na=ssrc:4167028587 msid:myDataChannel myDataChannel\r\na=ssrc:4167028587 mslabel:myDataChannel\r\na=ssrc:4167028587 label:myDataChannel\r\n"
  },
  "name": "test1"
}

我想知道它们之间共享了哪些端口信息。

Answer 1

正如@jib在评论中所述，端口是34965和49233。你可以在这里找到它们：

d8e8c8cc-a451-4eba-8251-3ac08c3548b6.local 34965
^^^ This is the obfuscated ip address ^^^ | ^^^^ This is the port number

13442325-85fc-4750-a0ed-1235f0b61bee.local 49233
^^^ This is the obfuscated ip address ^^^ | ^^^^ This is the port number

请注意，该IP是"XORed"，意思是隐藏/混淆，它的引入是为了防止在没有第三方服务的情况下能够获得用户的IP地址的安全问题。