We are getting audio only but no video when calling into conference with Cisco Jabber.   

Other SIP video clients (e.g Jabber) calling into the conference are OK. 

Sip negotiations are fine, SDP is fine and all parties agreeing on H.264 codec.  

The log (at debug level) doesn't show any relevant errors or warnings.

Any ideas what can be wrong and/or how to troubleshoot the problem?

Thank you

Ari