How to use just 1 channel when i transfer a Call to CM to other PABX

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Jan 18th, 2008
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When i receive a call through a MGCP GW QSIG for IP Phone, and IP Phone want transfert to a Phone on traditionnal PABX, i use 2 B Channel.

Is there a process to use just one.

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pcameron Fri, 01/18/2008 - 02:41
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This feature is called QSIG path replacement -

It allows the CallManager to signal the originating PBX to 'take back' the call and send it to a new extension on the originating PBX, this allows the B channel to be freed up , instead of having an inwards B channel and an outwards B channel as you have described.

Check if your QSIG PBX has this feature available.

sebastien.pecron Fri, 01/18/2008 - 05:06
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I have activated this function on Service Parameters

Path Replacement Enabled : True.

But i have always the same problem.

You say Check if your QSIG PBX has this feature available.

How i can check that.



pcameron Fri, 01/18/2008 - 05:30
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I can't answer how to check your PBX operation :-)

There are details on QSIG interoperability with many brands of PBX's here -

These guides mention how to set up path replacement on many of the models.

We worked on a Path Replacement issue with an NEC PBX a while back and eventually found that Path Replacement was an license option on the NEC that the customer had to pay extra to get enabled. Once they had it turned on, the feature worked perfectly between the PBX and the callmanager.

So first thing to do would be to speak to your PBX people to find out if they support it!


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