Conference call - 2 lines not disconnecting on hang up - SIP Grandstream Gateway 2

[curlycord]

PBX - Nortel Norstar CICS
Gateway - Grandstream HT818 Analog
Carrier - Rogers (Canada)

The carrier Rogers controls the Gateway, we have no access to it.
FYI for Canadian techs - They have started to do away with the traditional "Analog Modem with battery" direct to cable in favor of "Gateways" by Grandstream direct to Network switch.

The issue is a conference call is made via the Norstar system (in particular calling out from the mailbox using option 7), when both parties hang up the 2 lines/channels are still tied up.
The wiring needs to be disconnected briefly (I installed a BIX36B) or either the PBX or modem needs a reboot to free up the lines.
Single calls do disconnect and why I am puzzled.

Nortel Norstar CICS - I have confirmed "Disconnect Supervision" is programmed for all lines.
They carries support usually have no idea what ""Disconnect Supervision" means, but even more so now that it is now SIP and not POT's.


Has anyone had this same issue with Grandstream gateways? aside from "Disconnect Supervision" what should we be looking at on the Grandstream that I could convey to Rogers?
Any trickery?

Thanks

=----(((((((((()----=

http://www.curlycord.com

Toronto, Canada

Add me to LinkedIN

 

[libellis]

Floating out there .....somewhere.....there's an answer.....but at some point the effort is more than it's worth, so case closed indeed.