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one-way audio through a 6608 PRI Gateway to Nortel PBX

I have recently installed two ports of a 6608 blade as PRI gateway connections to a Nortel PBX. This allows for IP Phones to call Nortel Phones and the Nortel is also the IP Phones gateway to the PSTN. My problem is I have intermittent problems with one way audio. The IP Phone user cannot hear the PSTN or Nortel caller, but the Nortel or PSTN caller has no trouble hearing the IP Phoner user. The originating direction of the call is unimportant.

During one of these calls, iF you look at the call statistics on the IP Phone, RX and TX counts increment just as they do in a successful call. Statistics on the PRI gateway do not look unusual either.

Has anyone out there experiened this. Any possible solutions or troubleshooting advice.


Geoff Lenox

Qwest Communications

Cisco Employee

Re: one-way audio through a 6608 PRI Gateway to Nortel PBX

Make sure you are using the correct load for your version of callmanager accordign to this:

turn on detailed callmanager traces for the server where the GW is registered.

To see what q931 is doing do a search on the callmanager for a file called q931translator.exe

and run this, open the trace from there.

It sounds like callmanager is opening the audio path correctly. You can also do 'show port voice active' on the cat to see the GW stats.

Community Member

Re: one-way audio through a 6608 PRI Gateway to Nortel PBX

Hi Geoff, I've IPT system with a 3745 router-gateway into the PSTN via an E1 and a combination of 3750 & 3550's with 7960 & 7940's. To overcome the problem you've described I've had to use 12.2(15)T5 in the gateway and P00305000101 code in the IP phones. That has diminished the occurance of the probelm from an average of once every 2 hours to once every 7 or so days.

Hope this helps, rgds, Stuart

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