Google Nest Hub接收摄像头Offer SDP后无Answer SDP问题排查求助

问题前置信息 #

• 问题100%复现
• 同款摄像头在自身APP中可正常推流
• 已验证摄像头返回的Offer SDP合法有效
• 设备支持WebRTC流协议

具体异常情况 #

• 触发请求：Intent为action.devices.EXECUTE，执行命令为action.devices.commands.GetCameraStream
• 异常现象：摄像头云服务已返回正确的SDP信息，但始终未收到Google端的Answer SDP；部分场景下Google Nest Hub会主动发送"end"动作终止会话

交互数据详情 #

2023-03-22T13:23:16+0000 #

--
GoogleRequest:{"requestId":"8676804431427309387","inputs":[{"context":{"locale_country":"","locale_language":"sv"},"intent":"action.devices.EXECUTE","payload":{"commands":[{"devices":[{"id":"T8210P6421501817"}],"execution":[{"command":"action.devices.commands.GetCameraStream","params":{"SupportedStreamProtocols":["webrtc"]}}]}]}}]}
-- Response:{"requestId":"8676804431427309387","payload":{"commands":[{"ids":["T8210P6421501817"],"status":"SUCCESS","states":{"cameraStreamAuthToken":"euGo|r0iL11nuS_aSQPhSNtZlhg","cameraStreamIceServers":"[{\"urls\":\"stun:3.123.109.172:3478\"},{\"urls\":\"turn:3.123.109.172:3478?transport=udp\",\"username\":\"BXe1uTXXg8\",\"credential\":\"HbdIMOeTVjnWTPVe\"}]","cameraStreamSignalingUrl":"https://security-smart-eu.eufylife.com/v1/smart/google/webrtc?sessionId=81e50a34-44ad-4822-b97d-c187625d825c","cameraStreamOffer":"v=0\r\no=- 1679491395464 1679491395464 IN IP4 127.0.0.1\r\ns=Anker Webrtc Stream\r\nt=0 0\r\na=group:BUNDLE 0 1\r\na=msid-semantic: WMS fJpn2\r\nm=audio 1 UDP/TLS/RTP/SAVPF 0\r\nc=IN IP4 127.0.0.1\r\na=mid:0\r\na=sendonly\r\na=rtcp-mux\r\na=ice-ufrag:873o\r\na=ice-pwd:zGGsH/BaHndpznTe70Mvv/\r\na=fingerprint:sha-256 A9:07:34:CA:F8:6F:12:21:98:12:C9:D1:90:49:90:93:54:E6:6F:08:01:73:2C:81:F8:43:4B:75:BC:89:8D:3C\r\na=setup:active\r\na=rtpmap:0 PCMU/8000\r\na=ssrc:2200340691 cname:wz3l4Gc4\r\na=candidate:1 1 udp 2122317823 192.168.68.101 34512 typ host generation 0\r\na=candidate:2 1 udp 2122317567 192.168.32.2 34512 typ host generation 0\r\na=candidate:3 1 udp 1686109695 188.150.241.145 34512 typ srflx generation 0\r\na=candidate:4 1 udp 8387839 3.123.109.172 55137 typ relay generation 0\r\nm=video 1 UDP/TLS/RTP/SAVPF 98\r\nc=IN IP4 0.0.0.0\r\na=mid:1\r\na=extmap:2 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=sendrecv\r\na=rtcp-mux\r\na=ice-ufrag:873o\r\na=ice-pwd:zGGsH/BaHndpznTe70Mvv/\r\na=fingerprint:sha-256 A9:07:34:CA:F8:6F:12:21:98:12:C9:D1:90:49:90:93:54:E6:6F:08:01:73:2C:81:F8:43:4B:75:BC:89:8D:3C\r\na=setup:active\r\na=rtpmap:98 H264/90000\r\na=rtcp-fb:98 goog-remb\r\na=rtcp-fb:98 nack\r\na=rtcp-fb:98 nack pli\r\na=fmtp:98 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=rtcp-fb:98 ccm fir\r\na=ssrc:1180311490 cname:riolfAKg\r\n","cameraStreamProtocol":"webrtc"}}]}}]}

2023-03-22T13:23:17 #

{"sessionId":"81e50a34-44ad-4822-b97d-c187625d825c","action":"end","deviceId":"T8210P6421501817","sdp":""}

现寻求协助排查该问题的根本原因，感谢支持！

内容的提问来源于stack exchange，提问作者alexcrazy