1/2 Dropped calls over WAN.

[cartoondog1]

Using a VPN between sites, and it seems when either side initates a call all is good. 30sec into the call (most of the time, seems less likely to happen during off peak hrs) the remote branch site (site without the CM) can be heard by the Main branch party, but the remote branch party cannot hear what the main branch person is saying. Call is not dropped.

Any ideas where to start looking or how to trace? It is readily repeatable. All sites are using T1s and have minimal VOIP traffic. Typically one call concurrently going to branch locations. What I guess I am looking for are trouble shooting steps.

ICS 7750
CIsco CM 3.3.1
Phones 7960
Routers 2600

Thanks.

 

[ISDNman]

If this were a circuit switched network this would be easy!

I guess the first thing to do is put a protocol analyzer on each end (such as Ethereal wich is shareware) and look to see if packets are still arrive at the end with no audio.

Best of luck.

 

[JOAMON]

Might need to setup QOS for your voice traffic. If you do so remember that you need to add QOS pre-classify into the crypto-map statement.