I'm having an issue similar to thread690-1748520. I have Avaya SIP desk phones (9611G's), registered through Session Manager. They dial a TAC in CM that activates a loop-start trunk group connected to a paging adapter. I've tried a couple brands and made some calls to other adapter vendors. So far I haven't found a single-zone paging adapter that provides answer supervision. When I ask the vendors about answer supervision, I get "what's that?".. Without receiving Answer Supervision, Communication Manager never sends the 200 OK to the SIP phone (again, via SM) and the SIP continues to generate ring back.
There doesn't seem to be much information available on how analog trunk answer supervision works in general. What I could find talks about the CO reversing the battery polarity upon answer. I actually bought an DPDT relay with a 15ms switching time, connected coil to power through the paging adapter's aux contact port, so when the paging adapter detects the loop start from CM and picks up, the relay flips the polarity of the battery provided by the paging adapter. That's greats except it doesn't appear to be what CM was expecting because that did not cause CM to think the call was answered.
I have one location with an old Valcom multi-zone v-1109rthf that appears to provide answer supervision (because it works correctly), but I can't tell what it's doing (other than it plays a continuous tone to tell the caller to select the zone so maybe it's that tone that triggers CM to believe the call was answered).
Anyhow, my questions are thus:
1) Does anybody know of a analog loop-start trunk paging adapter that provides answer supervision?
2) Does anybody know what CM expects for answer supervision?
As an aside, if I program the trunk group type in CM as "wats" with "automatic" outgoing, CM sends the SIP phone a PRACK and the audio is cut through to the paging adapter. This is a workaround but is still garbage because (1) the phone doesn't really think the call got answered so it might drop the call early and (2) CM doesn't think the call got answered so it never records the call in CDR.
Thanks,
Sam
There doesn't seem to be much information available on how analog trunk answer supervision works in general. What I could find talks about the CO reversing the battery polarity upon answer. I actually bought an DPDT relay with a 15ms switching time, connected coil to power through the paging adapter's aux contact port, so when the paging adapter detects the loop start from CM and picks up, the relay flips the polarity of the battery provided by the paging adapter. That's greats except it doesn't appear to be what CM was expecting because that did not cause CM to think the call was answered.
I have one location with an old Valcom multi-zone v-1109rthf that appears to provide answer supervision (because it works correctly), but I can't tell what it's doing (other than it plays a continuous tone to tell the caller to select the zone so maybe it's that tone that triggers CM to believe the call was answered).
Anyhow, my questions are thus:
1) Does anybody know of a analog loop-start trunk paging adapter that provides answer supervision?
2) Does anybody know what CM expects for answer supervision?
As an aside, if I program the trunk group type in CM as "wats" with "automatic" outgoing, CM sends the SIP phone a PRACK and the audio is cut through to the paging adapter. This is a workaround but is still garbage because (1) the phone doesn't really think the call got answered so it might drop the call early and (2) CM doesn't think the call got answered so it never records the call in CDR.
Thanks,
Sam