I have the following problem (simplified a lot): I have Asterisk 13 running successfully, one end connected to a VoIP / SIP provider, the other end connected to three devices, namely two hardware SIP phones and one server-based SIP answering machine.
Inbound calls are signaled simultaneously to the phones and the answering machine. If nobody answers the call at one of the phones within 30 seconds, the answering machine answers the call. This works very well with the following exception:
There is no way to make the answering machine signal actively that it has got a call; I really can’t do anything about that (as said above, the answering machine is server-based, and you have to open the respective client software on a client PC to see its status).
The problem now is that the two hardware SIP phones do NOT signal calls which have been answered by the answering machine in any way, so I don’t know about such calls unless I open the answering machine’s client software. This is not what I want. I would like to make the hardware SIP phones ignore the information that a call has been answered by the answering machine and instead treat that call as if it had not been answered elsewhere at all. The hardware SIP phones then would signal such a call by blinking LEDs, and the caller’s number would be in the list of unanswered calls so that I could call back comfortably.
I tried to find a configuration option in the hardware SIP phones which would enable such behavior, but without success. Then I have been told that the PBX would be responsible for telling the phones what calls have been answered elsewhere.
So my question actually is: How could I modify my dialplan so that both hardware SIP phones signal an unanswered call if that call has been answered by the answering machine, but none of the hardware SIP phones signals an unanswered call if the call has been answered at the other one of the hardware SIP phones?
The relevant bit of my dialplan currently looks something like that:
exten => 08203xxxxx, 1, Dial(PJSIP/CuiTNitzpqXxzOYt&PJSIP/1rpiQqobew8CkaC7&PJSIP/20@bCo9m7OfHWK2Y2sb) same => n, Hangup()
08203xxxxx is one of my phone numbers; if an inbound call for that number comes in, PJSIP dials CuiTNitzpqXxzOYt, 1rpiQqobew8CkaC7 and 20@bCo9m7OfHWK2Y2sb simultaneously (please don’t wonder about those extensions … these are just hardware SIP phone 1, hardware SIP phone 2 and the SIP answering machine).