Hi,

I'd like to get your opinion on whether this WebRTC failure to connect points to a Chrome/VC or FS bug.

FreeSWTICH: 1.6.19
Verto Communicator: from v1.8 branch
Chrome: 59-61

Reproducer:
0. Chrome and FS on a local LAN
1. In VC, disable STUN as environment is local LAN
2. Chrome sends
2017-09-14 11:48:33.658249 [DEBUG] mod_rtc.c:389 () State Change CS_NEW -> CS_INIT
2017-09-14 11:48:33.658249 [DEBUG] switch_core_session.c:615 N/A set UUID=b138714b-740a-de23-101c-c76d5676a6d4
2017-09-14 11:48:33.658249 [NOTICE] switch_channel.c:1104 New Channel verto.rtc/3000 [b138714b-740a-de23-101c-c76d5676a6d4]
2017-09-14 11:48:33.658249 [DEBUG] mod_verto.c:3661 Remote SDP verto.rtc/3000:
v=0
o=- 3881351537341052870 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE audio video
a=msid-semantic: WMS Tub3STBaDw6tNMrINhAyvJBWK96IeIanerjj
m=audio 9 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 106 105 13 110 112 113 126
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:VU1P
a=ice-pwd:davKC7PLYeQ04ZkN4TNvGo9s
a=ice-options:trickle
a=fingerprint:sha-256 79:A5:79:AE:62:B9:7F:00:5F:0C:04:C1:18:81:C4:09:ED:47:3B:1B:0A:3C:2F:F2:7B:6F:D5:E7:3C:DA:E0:2C
a=setup:actpass
a=mid:audio
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=sendrecv
a=rtcp-mux

3. FS replies

[DEBUG] switch_core_media.c:3523 Searching for rtp candidate.
[DEBUG] switch_core_media.c:3523 Searching for rtcp candidate.
[DEBUG] switch_core_media.c:3567 verto.rtc/3000 no suitable candidates found.
[NOTICE] switch_channel.c:3812 Hangup verto.rtc/3000 [CS_EXECUTE] [INCOMPATIBLE_DESTINATION]
[DEBUG] switch_core_session.c:2815 verto.rtc/3000 skip receive message [APPLICATION_EXEC_COMPLETE] (channel is hungup already)

4. With STUN on, it connects successfully. Chrome sends the external NAT address (STUN discovered). This seems unnecessary for a local LAN.

5. For Firefox+VC without STUN, the verto.invite contains all the local LAN addresses and it connect successfully.

Any suggestions? Should Chrome+VC without be expected to work w/o STUN  on a local LAN while sending c=IN IP4 0.0.0.0?



--
Richard Chan