Freebpx 15 and Video on Grandstream Doorphone/Indoor Stations

Hope someone can point me in the right direction toward troubleshooting this issue. I have a tiny FreePBX 15 deployment at a site that is basically responsible for “fancying up” a Grandstream video doorphone system, essentially making the doorphone system work the way the client wanted, which could not be accomplished with just the Grandstream out of the box. I think the system is about 5 years old at this point, and had been working perfectly up until “recently”. I was involved in the initial setup but not the final configuration of the FreePBX install. Since that time the system has been updated sporadically, specifically when the time change comes in the spring and fall they will update both the OS and FreePBX with whatever updates are available at the time. Other than that, nothing has changed in the building so no config changes since initial install.

I got a call in to move one of the indoor stations and was met with a “we haven’t been able to see video of the person at the door for months now, can you check that while you’re here”. Tested and sure enough when the doorphone calls the indoor stations just show a black screen instead of the video. If I place a call from the indoor station to the doorphone I do get video (but in this case there may be some parameters forced as the indoor stations do have a “voice call” and a “video call” button in their dialer.

The only two other things that I can think might be relevant is that ring groups are used as the destinations that the doorphone dials and that I think they had it set up for early media (so you would see the video before you answered the call).

Based on “for months now” combined with the update schedule I can only assume that something broke when FreePBX updates were done last fall or this spring at the time change.

I really haven’t dealt with video in FreePBX so I’m just wondering if someone can tell me first steps to diagnosing why the video isn’t happening.

And a minor update… a couple of users have now confirmed that they never did have advance video, they always had to answer first before the video would start.