Jabber client iOS / Android / Windows / Mac not sending video to Webex conference

[Jakub Stroinski]

I have never been able to get this to work.

We have an on prem IM / Presence deployment with Expressway for MRA etc

When our users try to join a Webex conference by dialing the URI for the meeting i.e. user@company.webex.com, audio is connected and they are able to receive video but not send it.

If the user does the same from the Webex app on their device from the same network, it works. If we do this from a SX20 TP room, it works as well.

CUCM: 10.5.2

Expressway: 8.7.2

Most recent Jabber clients for all platforms

Any ideas on where to look?

Thanks!!!

[Jakub Stroinski]

Bump?

We've upgraded our Expressway to x8.7.3 and kept our Jabber clients up to date.

No change. Still unable to send video from our Jabber clients.

[jecker]

Any resolution to this issue?  I'm having an issue with mobile devices registered to Expressway getting video calls VCS 8.8 and CUCM 11.0. 

Thanks.

[Jakub Stroinski]

Actually yes

We did logging in the Expressway and turns out that we had a double NAT issue in the firewall that was overwriting the source address of the Webex bridge to its own address so the media was dying in the firewall and never making its way back to Webex.

In the logs, the source Webex and destination Webex address needs to be one of the Webex public addresses.

Turns out as well that we had a problem with our audio codec preference list. We had modified the codec preference list to use G729a as first preference to save bandwidth. Turns out that Webex negotiates with other codecs (like G722) and doesn't want to talk to G729 especially for the DTMF negotiation if a host PIN etc needs to be entered. An error 488 was being shown in the call history logs. We put it back to default low loss and the problem went away.