Hi,
We have a site that is gradually migrating from a Meridian Option 1 to a Mitel cluster of systems - two trunking gateways and an ISS server for users.
We originally had QSIG trunks set up between the Meridian and trunking gateways which worked fine except that the Meridian consoles couldn't camp on or release calls to busy extensions on the Mitel ISS server.
In order to fix this we now have changed to DPNSS trunks however this has now caused another issue.
Incoming calls to a DDI on the ISDN connected to the Meridian are forwarded to an extension on the Mitel controller via the trunking gateways. All works fine except some users do not have voicemail and if the phone is busy the incoming caller gets NU even though the Mitel returns a busy code in the CCS trace.
Before you all say it must be the Meridian if I reverse the scenario and set up an incoming DDI call on a SIP trunk to the Mitel gateway that is routed via ARS to a Meridian extension we get exactly the same.
Internal calls in either direction to busy phones return busy tone as expected.
I have tried the system options qsig/dpnss diversion set as yes or no, checked the direct IP routes on the Mitel cluster have trunk to trunk and public access via dpnss allowed in COS 100, checked the DPNSS COS has trunk to trunk allowed, blanked out the auto camp on timers.
Running out of ideas now so any suggestions would be gratefully received.
PS if we revert back to QSIG it works as expected and the incoming caller gets busy tone
TIA Julie