为什么 sipml5 为音频 RTP、音频 RTCP、视频 RTP 和视频 RTCP 创建具有相同端口的 webRTC 邀请请求？
Why sipml5 create webRTC invite request with same port for Audio RTP, Audio RTCP, Video RTP and Video RTCP?
之前我使用firefox web 浏览器发起webRTC 邀请请求。然后我观察了音频和视频通道具有不同端口号的 sdp。而且我可以轻松获得候选人并完成 ICE 操作。在这里，我在 chrome 网络浏览器中附加了 webRTC 邀请请求消息。
INVITE sip:user1@myserver.demo.com SIP/2.0
Via: SIP/2.0/WS df7jal23ls0d.invalid;branch=z9hG4bK2d4AlD4kTtu3AvTbW7RZDD03H1Ex8MnB;rport
From: "user2"<sip:user2@myserver.demo.com>;tag=gy75qhB7Gxto2pakdTaT
To: <sip:user1@myserver.demo.com>
Contact: "user2"<sip:user2@df7jal23ls0d.invalid;rtcweb-breaker=no;click2call=no;transport=ws>;+g.oma.sip-im;language="en,fr"
Call-ID: 1290ebe1-f59d-95c3-a91c-d714773ae56b
CSeq: 37591 INVITE
Content-Type: application/sdp
Content-Length: 3709
Max-Forwards: 70
User-Agent: IM-client/OMA1.0 sipML5-v1.2014.12.11
Organization: Doubango Telecom
v=0
o=- 3376022867449415700 2 IN IP4 127.0.0.1
s=Doubango Telecom - chrome
t=0 0
a=group:BUNDLE audio video
a=msid-semantic: WMS Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
m=audio 57008 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 126
c=IN IP4 202.53.167.164
a=rtcp:57008 IN IP4 202.53.167.164
a=candidate:2068563606 1 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:2068563606 2 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:902314598 1 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:902314598 2 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:3083270405 1 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=candidate:3083270405 2 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=ice-ufrag:cinBWZB6tiSnOnf1
a=ice-pwd:50yVBGm5WuKlbZeyRrmjOvMn
a=ice-options:google-ice
a=fingerprint:sha-256 7C:69:84:B5:D5:C1:86:D0:56:8F:22:BA:5F:61:AD:1E:55:21:5A:6A:50:35:0C:49:E2:43:E9:C0:03:CC:B5:31
a=setup:actpass
a=mid:audio
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=sendrecv
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=fmtp:111 minptime=10; useinbandfec=1
a=rtpmap:103 ISAC/16000
a=rtpmap:104 ISAC/32000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:106 CN/32000
a=rtpmap:105 CN/16000
a=rtpmap:13 CN/8000
a=rtpmap:126 telephone-event/8000
a=maxptime:60
a=ssrc:4060942202 cname:MV0YBQDo4IyYKk2T
a=ssrc:4060942202 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 8031161b-973f-4024-8f52-7bd33af05431
a=ssrc:4060942202 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:4060942202 label:8031161b-973f-4024-8f52-7bd33af05431
m=video 57008 UDP/TLS/RTP/SAVPF 100 116 117 96
c=IN IP4 202.53.167.164
a=rtcp:57008 IN IP4 202.53.167.164
a=candidate:2068563606 1 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:2068563606 2 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:902314598 1 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:902314598 2 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:3083270405 1 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=candidate:3083270405 2 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=ice-ufrag:cinBWZB6tiSnOnf1
a=ice-pwd:50yVBGm5WuKlbZeyRrmjOvMn
a=ice-options:google-ice
a=fingerprint:sha-256 7C:69:84:B5:D5:C1:86:D0:56:8F:22:BA:5F:61:AD:1E:55:21:5A:6A:50:35:0C:49:E2:43:E9:C0:03:CC:B5:31
a=setup:actpass
a=mid:video
a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=sendrecv
a=rtcp-mux
a=rtpmap:100 VP8/90000
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=rtcp-fb:100 goog-remb
a=rtpmap:116 red/90000
a=rtpmap:117 ulpfec/90000
a=rtpmap:96 rtx/90000
a=fmtp:96 apt=100
a=ssrc-group:FID 992785727 3894832329
a=ssrc:992785727 cname:MV0YBQDo4IyYKk2T
a=ssrc:992785727 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:992785727 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:992785727 label:85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:3894832329 cname:MV0YBQDo4IyYKk2T
a=ssrc:3894832329 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:3894832329 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:3894832329 label:85987089-827b-4f5a-a7ff-65afc1c23f88
那么，为什么他们使用相同的端口号以及如何处理这些端口号以进行 ICE 检查？
导致浏览器只使用一个音频和视频连接的行是
a=group:BUNDLE audio video
您只需从 offer/answer 中删除此行，浏览器将继续使用多个连接。
之前我使用firefox web 浏览器发起webRTC 邀请请求。然后我观察了音频和视频通道具有不同端口号的 sdp。而且我可以轻松获得候选人并完成 ICE 操作。在这里，我在 chrome 网络浏览器中附加了 webRTC 邀请请求消息。
INVITE sip:user1@myserver.demo.com SIP/2.0
Via: SIP/2.0/WS df7jal23ls0d.invalid;branch=z9hG4bK2d4AlD4kTtu3AvTbW7RZDD03H1Ex8MnB;rport
From: "user2"<sip:user2@myserver.demo.com>;tag=gy75qhB7Gxto2pakdTaT
To: <sip:user1@myserver.demo.com>
Contact: "user2"<sip:user2@df7jal23ls0d.invalid;rtcweb-breaker=no;click2call=no;transport=ws>;+g.oma.sip-im;language="en,fr"
Call-ID: 1290ebe1-f59d-95c3-a91c-d714773ae56b
CSeq: 37591 INVITE
Content-Type: application/sdp
Content-Length: 3709
Max-Forwards: 70
User-Agent: IM-client/OMA1.0 sipML5-v1.2014.12.11
Organization: Doubango Telecom
v=0
o=- 3376022867449415700 2 IN IP4 127.0.0.1
s=Doubango Telecom - chrome
t=0 0
a=group:BUNDLE audio video
a=msid-semantic: WMS Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
m=audio 57008 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 126
c=IN IP4 202.53.167.164
a=rtcp:57008 IN IP4 202.53.167.164
a=candidate:2068563606 1 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:2068563606 2 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:902314598 1 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:902314598 2 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:3083270405 1 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=candidate:3083270405 2 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=ice-ufrag:cinBWZB6tiSnOnf1
a=ice-pwd:50yVBGm5WuKlbZeyRrmjOvMn
a=ice-options:google-ice
a=fingerprint:sha-256 7C:69:84:B5:D5:C1:86:D0:56:8F:22:BA:5F:61:AD:1E:55:21:5A:6A:50:35:0C:49:E2:43:E9:C0:03:CC:B5:31
a=setup:actpass
a=mid:audio
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=sendrecv
a=rtcp-mux
a=rtpmap:111 opus/48000/2
a=fmtp:111 minptime=10; useinbandfec=1
a=rtpmap:103 ISAC/16000
a=rtpmap:104 ISAC/32000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:106 CN/32000
a=rtpmap:105 CN/16000
a=rtpmap:13 CN/8000
a=rtpmap:126 telephone-event/8000
a=maxptime:60
a=ssrc:4060942202 cname:MV0YBQDo4IyYKk2T
a=ssrc:4060942202 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 8031161b-973f-4024-8f52-7bd33af05431
a=ssrc:4060942202 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:4060942202 label:8031161b-973f-4024-8f52-7bd33af05431
m=video 57008 UDP/TLS/RTP/SAVPF 100 116 117 96
c=IN IP4 202.53.167.164
a=rtcp:57008 IN IP4 202.53.167.164
a=candidate:2068563606 1 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:2068563606 2 udp 2122194687 192.168.10.148 57008 typ host generation 0
a=candidate:902314598 1 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:902314598 2 tcp 1518214911 192.168.10.148 0 typ host tcptype active generation 0
a=candidate:3083270405 1 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=candidate:3083270405 2 udp 1685987071 202.53.167.164 57008 typ srflx raddr 192.168.10.148 rport 57008 generation 0
a=ice-ufrag:cinBWZB6tiSnOnf1
a=ice-pwd:50yVBGm5WuKlbZeyRrmjOvMn
a=ice-options:google-ice
a=fingerprint:sha-256 7C:69:84:B5:D5:C1:86:D0:56:8F:22:BA:5F:61:AD:1E:55:21:5A:6A:50:35:0C:49:E2:43:E9:C0:03:CC:B5:31
a=setup:actpass
a=mid:video
a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=sendrecv
a=rtcp-mux
a=rtpmap:100 VP8/90000
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=rtcp-fb:100 goog-remb
a=rtpmap:116 red/90000
a=rtpmap:117 ulpfec/90000
a=rtpmap:96 rtx/90000
a=fmtp:96 apt=100
a=ssrc-group:FID 992785727 3894832329
a=ssrc:992785727 cname:MV0YBQDo4IyYKk2T
a=ssrc:992785727 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:992785727 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:992785727 label:85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:3894832329 cname:MV0YBQDo4IyYKk2T
a=ssrc:3894832329 msid:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b 85987089-827b-4f5a-a7ff-65afc1c23f88
a=ssrc:3894832329 mslabel:Jyup2XWPA5tOgvau9NIBMjlZFQzSEl6g3P0b
a=ssrc:3894832329 label:85987089-827b-4f5a-a7ff-65afc1c23f88
那么，为什么他们使用相同的端口号以及如何处理这些端口号以进行 ICE 检查？
导致浏览器只使用一个音频和视频连接的行是
a=group:BUNDLE audio video
您只需从 offer/answer 中删除此行，浏览器将继续使用多个连接。