Hi..

We integrated the CUCM 6.0 with Nortel 81c using H.323. Below is the scenario:

CUCM6.0--------Switch--------NortelServer

! !

! !

Cisco IP Phone Nortel IP/Dig/Ana PH

We have configured the CUCM and Nortel using attached Cisco Document and tested below scenarios:

1. Called from Cisco IP Phone to Nortel IP, Digital and Analog Phones. Everything is working fine(voice is flowing both the way).

2. Called from Nortel Digital and Analog Phones to Cisco IP Phone. In this case also everything is working fine(voice is flowing both the way).

3. In this scenario we called form Nortel IP Phone to Cisco IP Phone. The issue is that the Voice is flowing only form Nortel IP Phone to Cisco IP

Phone and not from Cisco IP Phone to Nortel IP Phone.

Taken the packet captures at both CUCM and Nortel Phone end(attached below). From logs what I found is, when Nortel IP Phone is replying to CUCM on the negotiated UPD port,

that port is unreachable and giving ICMP (Destination Unreachable). There may be other issue also which I haven't observed. Does anyone know what could be the problem?

Need urgent help.Thanks in advance..........