[Freeswitch-users] Add & remove video from active call

I'm using FreeSWITCH as a WebRTC portal to our existing SIP phone system. I am able to establish an initial audio/video call between 2 WebRTC users. I'm trying to add the ability for a user to disable, then re-enable the video portion of the call. I've modified SIP.js slightly to allow me to re-INVITE with or without the video portion of the call and FS handles that quite well. The problem I'm having is that FS does not forward the re-INVITE on to our phone system. The other user never knows that the first user has disable video. They simply get a black rectangle where the video had been. Does this capability exist or will we need to add it? Thank you, Dan