A : polycom group700 ver5.1.2 1080p 4mp
B : lifesize team220 4mp
C : polycom group700 ver5.1.2 1080p
What is the problem??
What network(s) are involved? Firewalls? What protocol(s) used for calls?
H323 and no firewalls.
Are they all on the same local network or going thru Internet or MPLS?
Have you looked at the CALL STATISTICS during a problem call?
Maybe the SYSTEM LOGS show something relating to video protocol/resolution negotiation.