Try these steps. I wrote this based on System Manager but you can also run the appropriate commands directly in Communication Manager.
1. Set Video on the Trunk Group(s) between Session Manager and Communication Manager
a. On the System Manager interface, in the Elements column, click Communication Manager > Parameters > System Parameters – Customer Options.
b. Click the arrow icon next to the Select Device(s) from Communication Manager list.
c. Select the appropriate Communication Manager and click Show List.
d. Select the radio button in the first column and click View.
e. Click Next Page until you navigate to Page 4. Ensure the feature Multimedia IP SIP Trunking is set to y.
2. Enable video for the SIP signaling group.
a. On the System Manager interface, in the Elements column, click Communication Manager > Network > Signaling Groups.
b. On the Signaling Groups page, click the arrow icon next to Select Device(s) from Communication Manager list.
c. From the Communication Manager list, select the appropriate Communication Manager instance, and click Show List.
d. Select the appropriate Signaling Group Number and click edit to set parameters as mentioned below:
• IP Video: y
• Direct IP-IP Audio connections: y
• Initial IP-IP Direct Media: y
3. Add video to IP-codec-set.
a. On the SAT screen, enter change ip-codec-set n, where n is the codec set number used by SIP signaling group.
b. Add or change the appropriate audio codecs as required. Set the following Multimedia parameters on page 2:
• Allow Direct-IP Multimedia: y
• Maximum Call Rate for Direct-IP Multimedia: 1024 Kbits
Note: These values are examples only. 1024 allows for 720p High Definition. Higher resolutions require more bandwidth. See Avaya Video Telephony Solution Release 5.2 Networking Guide for further details.
• Maximum Call Rate for Priority Direct-IP Multimedia: 2048 Kbits
Note: This applies to priority video users and is not required for minimal administration. See Avaya Video Telephony Solution Release 5.2 Networking Guide for further details.
Note: Verify that the list of audio codecs on the first page includes at least one of the audio codecs supported by the video endpoint, such as G.722 or G.711.