I have two sx10s configured to test with... Well both devices are registered with CUCM, can make and received calls from any device in the cluster. Both devices can call each other, the audio is flowing but no video.
Device sip profile is set to : Telepresence conferencing. in CUCM.
However, if i change the SIP profile for: Telepresence END point. Calls between the two sx10s, drop after the first rings with error :
SIP/2.0 503 Service Unavailable Reason: Q.850;cause=47