Answer supervision works together with the type of signaling used.
If you use “loop start”,then you could enable tone based supervision, and then the delays will work.
But if your signaling is anything but “loop start”, all the settings for tone supervision, included the “delay”, doo not work at all.
Step one: Set the “CAS signaling type” to “loop start”, or option 1.
Step 2:Set the “supervision” to “answer” ,or option 2.
Step 3:Set “asnwer delay timeout” to something like 60 seconds.
The way that it works: Wehn a call comes in from the VOIP side, the equipment will dial out the call to the PSTN and wait for a valid voice that indicates that someone answered the call.
If the call is not answered in a time shorter than the :answer delay timeout”, the gateway will consider tha call “answered”, even if it still ringing.
If anyone answer the call before the “answer delay timeout”, the gateway will send a “start of communication” back to the originating gateway/switch.
Troubles: If you get a recorded message, like a answering machine,voice mail, or one of those message that says “the person that you are calling is not reachable now”, that will be consider a valid answer.
if that is not aceptable, and you have only loop start lines, there is no cheap solution.