Dear Nortel PBX Techs,
We have a software IVR application that has been compatible with Meridian Option 81 & Option 11 for years and uses a T1 interface for the voice connection. For the past few years we have generally used a NT5D11AE model T1 card programmed with 500 Stations for each channel in a simple OPX-style interface. The circuit card is configured with jumpers to use D4 framing, AMI line coding and loop start protocol. We became very familiar with the robbed-bit signalling the switch would provide to indicate call arrival, seizure, and diconnect and configured our software to recognize these successfully.
I anticiapte some changes have occurred recently in either the model of T1 card or firmware for it which Nortel currently releases to site. Could someone please provide any resources I could investigate to help determine if changes occurred, specifcally in relation to how a loopstart digital circuit would be administered?
It could be that we have just run into a rash of people who are not familiar with conguring the Nortel exactly how we need it to be, but from what I can tell -- they have configured things correctly.
We are able to establish the actual DS1 link no problem, so I am confident the basic pinout, framing, and line coding have been attended to properly.
Our primary difficulty currently is that te switch is able to deliver a ringing call to a port, and our application sees the signal and answers. Everything goes according to plan, although we seem to lack the expected bit change (a-1) when the call disconnects.
To the best of our ability we have narrowed this down to Rev.2 of the above board works whereas Rev. 3 does not.
Any thoughts would be appreciated. Thank you!
Tony