Layout as follows:

(Site office)Analogue Handsets->PBX->EM Trunk->Voice Gateway--->IP(SIP)--->Voice Gateway->T1 Trunk->Digital PBX->Digital Handsets(Head office)

Problem:

1. Calls made from the head office digital handsets to the site office analogue handsets consistently drop after 3 minutes.

2. Calls from the site office analogue handsets cannot call through to head office. Debugging 'voice dialpeer' and 'voip vtsp' seem to show that no digits are being received by the voice gateway over the E&M trunk. Loopback tests on the PBX seem to confirm that digits are being sent over E&M trunk.

Troubleshooting to date:

(Regarding point 1 above)

Configured site office 2811 voice gateway to support CIPC (using telephony-service setup). Called to CIPC phone from head office digital handset. Call did not drop after 3 minutes. This seems to indicate that it is the E&M trunk or the PBX that is causing the call to drop.

(Regarding point 2 above)

Attached is debug output of 'debug voip vtsp all' showing the moment when the call is dropped. Would be grateful if somebody could shed some light on why this is happening.

I'm pretty certain the E&M cards are faulty, but am happy to be proved wrong if anyone has experience of this kind of error.

Much appreciated.