Scenario# 48 – Desktop share won’t work Jabber conference call

I was working on an issue for a client where they were not able to share screen if there are 3 or more particpants in a jabber conference call.

They tested it on Jabber 10.6.1 and 10.6.6 but had same issue.

Chat only conference works fine if there are 3 or more particpats. 5 is the limit at the moment for Jabber desktop share. Not sure if it will be increased in future relases.

Anyways, we made several test calls with 4 users all connected to Jabber in soft client mode, registered to same cucm and on same cups cluster. I couldn’t find anything useful in Jabber problem report. In CUCM, however, I noticed that BFCP protocol changes IP to 0.0.0.0 in ACK even though INVITE goes with proper and correct IP of conference initiator. You will see something like below:
v=0
o=CiscoSystemsCCM-SIP 75015974 5 IN IP4 10.1.35.2
s=SIP Call
b=AS:64
t=0 0
m=audio 24682 RTP/AVP 0
c=IN IP4 10.1.35.2
a=ptime:20
a=rtpmap:0 PCMU/8000
m=video 0 RTP/AVP 126
c=IN IP4 10.111.5.166
b=TIAS:352000
a=label:11
a=rtpmap:126 H264/90000
a=fmtp:126 profile-level-id=42E01F;packetization-mode=1;max-fs=3601;max-rcmd-nalu-size=32000;level-asymmetry-allowed=1
a=content:main
a=inactive
m=video 0 RTP/AVP 126
c=IN IP4 10.111.5.166
b=TIAS:352000
a=label:12
a=rtpmap:126 H264/90000
a=fmtp:126 profile-level-id=42E01F;packetization-mode=1;max-fs=9001;max-rcmd-nalu-size=32000;level-asymmetry-allowed=1
a=content:slides
a=inactive
m=application 0 UDP/BFCP *
c=IN IP4 0.0.0.0

I had to log a TAC case for this and even he struggled a bit to find out why it is not working. Later he confirmed that BFCP* protocol does not support phone conference calls if MCU is not used as Conference Bridge. You must add a conductor / MCU to use desktop share in a conference call of 3 or more participants. This is nowhere documented in any Cisco documentation which the TAC agreed as well and it will be added in future release notes of Jabber.