A Nortel Meridian system in site A is connected to the Callmanager 4.2(3)system in Site B. There is an MGCP Cisco 3825 voice gateway in Site A acting as the voice gateway between the 2 systems.
When dialling between the 2 sites the call connects without any problem.
All of the Cisco phones in Site B have a busy trigger of 1.
When calling a phone in Site B from the Nortel Meridian phones in Site A, if the called party is busy then the call drops instead of following the forward busy setting in Callmanager.
When calling from Cisco phone to Cisco phone in Site B this is not a problem. In addition the call forward no answer between the 2 sites is fine.
Please can you help me to troubleshoot this.
If it's a QSIG, try ECMA Variant instead of ISO (if possible with Merifian)