ISDN for Voice and Video

Unanswered Question
Sep 7th, 2010

Hi guys

We are change the PBX NEC for UCM 8.0

The PBX NEC has 2 ISDN PRI and 2 extensions are VideoConference. The both ISDN PRI receive voice calls and video calls. How the router do to known if is a voice call or a video calls? Is there a particular configuration on router to this works?



I have this problem too.
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Brandon Svec Tue, 09/07/2010 - 20:03

It should just be based on DID number.  I assume BRI video units? Ask the NEC tech to look to see what DID numbers are pointed at the video units.


pgcristovam Tue, 09/07/2010 - 20:09


On router not have BRI, just PRI to both ISDN and fxs to analog phones

Brandon Svec Tue, 09/07/2010 - 20:53

Well, I was just guessing about the BRI video units, but if they exist

and you need to make them work on your new Cisco solution you may need

to get a BRI module.

On Sep 7, 2010, at 8:09 PM, pgcristovam

pgcristovam Wed, 09/08/2010 - 03:50


If I have a BRI. The router do the change of initical voice call to video call? Remember on both ISDN PRI receive voice and video calls.

Thanks a lot


Brandon Svec Wed, 09/08/2010 - 06:53

Sure. The same way you make a DID ring a particular telephone.

On Wed, Sep 8, 2010 at 3:50 AM, pgcristovam <

Steven Holl Wed, 09/08/2010 - 07:38

The ISDN circuit should have a bearer cap of unrestricted digital.  What is the topology on the other call leg for the video calls?  Is that h323?  Or is it another ISDN circuit?

If it is ISDN to ISDN, keep the calls on the same DSP, and the gateway simply needs to just pass q931 between the two circuits.

If one of the legs is IP video, then the gateway needs to be configured for an h320 gateway:


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