After you configure the Video Telephony between 7970 and 7960 as well as between 7970 and CIPC 2.0, there is no video window displayed on the screen. The camera is associated with the devices and also video is enabled on the Cisco CallManager.
It has been observed that this issue occurs if a step is missed in the configuration. In order to resolve this issue, make sure that these occur:
The IP-to-IP Calls has two-way audio.
The Video Telephony Advantage (VTA)works on the PC itself, without any calls to/from them.
The phones are in the same Device Pool, that would mean they have same Region assigned.
Phones have Location assigned to them.
Region and Location has enough bandwidth given for Video Calls.