Webrtc using puplic ip not hear


Hello everyone
I have use UCM6202 firmware
when I call using webrtc using public ip it has no voice.
I using google chome Version 77.0.3865.90 (Official Version) (64 bit) and the latest firefox but it’s the same.
Is that a problem of UCM.
Thankscapture-000B82E4EC41.zip (3.6 MB)


you activated both voice and video codecs?
that you did the NAT with the ACL?


I have activated both voice and video codecs.
I using ipphone video ok, but webrtc not ok.


you activated the appropriate NAT as I wrote on them?

try to use WebRTC inside the LAN, if it works properly you know that the problem is external, so Firewall not set correctly


The capture is not complete as it only shows the 3370 and UCM communications and not that to the outside. You need to do a capture using all interfaces.


I have use webrtc insite the LAN ok, webrtc problem is external.
I do not have a firewall, so a firewall is not a problem, because i can use external ip phone and softphone ok


ok will capture all UCM and PC


not having a firewall is a GRANT error, you NEVER expose to the whole world one or more ports, for reasons of security and smooth operation.
Moreover, without a firewall you can not monitor where exactly the problem is, if locally webrtc works at this point the problem you have to search outside of UCM.


thanks @damiano70 I am running a test, so I don’t go through the firewall to see if the problem is with the firewall.


I have capture log when calling by webrtc with public ip but not hear
I think grandstream has problem with webrtc with public ip.
log call web.zip (107.2 KB)


I remember that GS have problem with NATing SDP (or rather lack of it).
Log - data is encrypted, not much can read.

If you can switch to http and do again test with log and check if SDP is NATed or not.


I had no issue in using HTTPS and port 8089 with a fqdn for WAN access. I was using Chrome Version 77.0.3865.120 (Official Build) (64-bit) at the remote site and a GXV3275 across a VPN for the other end. The only thing I had to do was to unmute the Chrmoe side of things as when it first starts the microphone is muted.

I also tried Firefox 69.0.3 (64-bit) and had no issue.

You did not state what other device or web client was in use in the conference as I assume there must have been at least one other.