Video calls not working from FreePBX to Grandstream UCM by SIP Trunk

Hi. I have a GDS3710 Doorbell and a GXV3240 SIP phone. Video calls work great when both devices are registered on FreePBX. I have a grandstream UCM PBX and video calls work fine when the phones are connected directly to it. Right now I have a peer sip trunk setup with the grandstream UCM PBX and FreePBX. I can place phone calls fine between the 2 and the audio works but I cant seem to make a video call. The extensions are using PJSIP and I have a PJSIP trunk. Does anyone know off hand as to what could be causing this? I will have to upload my packet capture results a little bit later.

Maybe a codec mismatch? Probably the end devices understand each other when on the same PBX only, given that video is passthrough.

Here is what the call flow looks like in Wireshark. is the Grandstream UCM and is FreePBX is the video phone

callee has no offers video codec(H264)?

Here is my call flow showing the video Door Bell (IP: (Connected to FreePBX) going to
FreePBX ( then from FreePBX to Grandstream ( to the video phone (

I have a custom extension 6331 that dials extension [email protected] (video phone extension @ trunk name of grandstream pbx).

Here is my extensions_custom.conf for FreePBX

exten => 550,1,Dial(PJSIP/[email protected],60,m(Cisco)b(callHandler^callee_handler1^1))
exten => 550,2,Hangup

exten => 6332,1,Dial(PJSIP/[email protected],60,m(Cisco)b(callHandler^callee_handler2^1))
exten => 6332,2,Hangup

exten => s,1,System(HIDE THIS INFORMATION)
exten => s,n,MacroExit

exten => s,1,System(HIDE THIS INFORMATION)
exten => s,n,MacroExit

exten => callee_handler1,1,NoOp()
same => n,Set(__DYNAMIC_FEATURES=Door1)
same => n,Return()

exten => callee_handler2,1,NoOp()
same => n,Set(__DYNAMIC_FEATURES=Door2)
same => n,Return()

Found the issue.In my pjsip.endpoint.conf my trunk (UCM6208) didn’t have codec H264 listed. I added that and now when the call gets routed from FreePBX through the trunk we are all good! Hope this can help someone else too!

Well if it works with Asterisk you might want to file a feature request to get it in the GUI

Hey good idea. I just checked and noticed that a feature request is already in there from 2017(FREEPBX-15853). I added my vote.

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