Video conference, converting to audio only - Confusing

[Dieselboy]

I have set up a video conference profile for our CUCM and 2921 router. This is working good, I can video conference with 4 people. I have configured maximum participants as 4.

However, we can audio conference up to 8 participants. Prior to the additional config to enable video conferencing, we have already configured and working, audio conferencing. The capabilities of this are 4 concurrent sessions, and up to 8 participants per session.

So my problem is: Our endpoints are video enabled (desk phones and Jabber). If I set up a conference, by default it is a video conference. I cannot add a 5th person to this conference because the capability is up to 4. I expected a 5th person would send the conference into an audio-only conference and drop all video between all users. ie turn it off. But instead I just get an error "Cannot add person to conference" or something along those lines.

So how do I get to an audio only conference with up to 8 people per session? Seems by enabling video conferencing, I've broken audio conferencing. TAC case raised, but the engineer didn't know how to enable video conferencing so I'm not enthralled with confidence.

[RHochstenbach]

I'm not really experienced with the CUCM, but on Tandberg/Codian equipment a participant limit means that all connections above that limit are dropped. Audio-only participants are usually only created when exceeding the ports (screen license) limit.

[Dieselboy]

Thanks for your reply. I could not get this working the way I wanted. It seems I have two options:
1. completely remove the audio conference bridge, all conferences will be video-capable.
2. TAC suggested to increase the participant limit, to 3, before invoking a conference bridge. I've not tested this option yet.

At the moment, I've disabled video conferencing.