Dead Air on PRI's

[TelcoTech]

We just turned up two PRI's with our carrier that go to seperate 3845 cisco gateways. We are getting dead air on all test calls on both circuits. So far we have captured the voice sessions from the DSP's and decoded to wave file. We can hear the R-in stream from Unity in the recordings, but the S-in from the provider is blank. Our issue is that call setup is occurring successfully between carrier and our equipment, so they say its not on their end. What else or what tests can I ask the telco to perform to ensure their routing is correct for the voice traffic over the B channels?

 

[pndscm]

Make sure your router cards have the correct timing options. Usually you want to time from the Line. Do 'show controller T1 X/X/X' and check your line errors. Sounds like you have T-1 issues.

 

[TelcoTech]

The clocking checks out ok. Here is the latest from testing. The carrier can loop to the NIU and can receive echo replies ok. When we have a call up, I can inject tone from the router towards the network and can hear the tone on an IP phone. If I try to inject the tone towards the carrier it cannot be heard. It would seem that its testing good from carrier to NIU and from Router to IP phone. SO...........could cabling between the NIU and the router interface in anyway cause this type of problem?? Remember the D channel and B channels are up and passing Q931 messaging.

 

[whykap]

I don't think your issue is with the PRI. Sounds like you have a routing issue or possibly a codec mismatch.