I just installed VCS X7.2 and CUCM 9.1.2 using the doc you referenced and I am able to do video from outside callers (via VCS-E) to all video endpoints/devices registerd to CUCM (9971, Jabber, MX300, and MCU). So, the products will work together.
I'd suggest taking a look at your region settings to ensure you aren't blocking video somehow. I assume that if you followed the guide correctly that you have ensured that SIP profiles, trunk security profiles, SIP trunks, normalization scripts, etc. are all configured correctly. I know that 9.1 has a pre-canned normalization script for VCS and a specific SIP profile.
1. Check the VCS search history to ensure that the search request is found (which I am sure it is)
2. If the call connected (even if media failed) then it may be worthwhile looking at the call history on VCS, find your call and drill in to see if you can find anything of interest.
3. On CUCM, you can use RTMT Session Trace to get information on the SIP session set up. It is a pretty handy tool that reads the call traces and renders them in an easy-to-navigate ladder diagram. You will want to look at the SIP messages that include the SDP information. It should help identify media negotiation issues. You can also do a SIP call trace on CUCM (if you prefer).
I did a write up on the RTMT Session Trace tool here:
I was wondering if you found a resolution to your issue?. We are experiencing a very similar issue and it would be interesting to know what others have seen. We have done many traces and drilled into the calls on VCS to no avail.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...