Error doing conferences between Cisco and Nortel phones

[reg_cisco]

Hello everybody.

I have two different infraestructures in my telephony network.

One Cisco, with one publisher, a suscriber and two voice gateways, one of them connected with a Nortel CS-1000 PBX by a QSIG.

When I try to do a conference between a Cisco and a Nortel, the Nortel phone leaves the conference itself.

Between Cisco phones, there is no problem.

Can anybody help me?.

Thanks in advance

[Manish Prasad]

How do you integrated Cisco with Nortel ? Which protocol ?

Does the Trunk/GW between Cisco and Nortel contains CFB in its MRGL ? Which all codec are in use when you do conference ?

If there is mismatch in codec then you need Xcoder for this.

[Kirill Glushenkov]

Hello!

'one of them connected with a Nortel CS-1000 PBX by a QSIG..'using E1/T1? If yes, try to use 'debug isdn q931' to see, who sends release message. If it goes from CUCM, then go through steps that Manish has suggested.

Regards,

Kirill

[Brian Meade]

Attach CallManager traces for one of these calls.