[asterisk-users] Confirm answering a call

[Mark Scholten]

Hello,

I am working on getting the following to work and I couldn't find it in the
documentation I did read. Where should I look or does someone have an
example how I can do it?

Current situation:
Incoming call -> 3 SIP phones + 2 mobile phones ring -> if mobile phone goes
to voicemail the call is answered by that voicemail (if a phone is in use
for another call the call directly goes to that voicemail)

Situation I want:
Incoming call -> 3 SIP + 2 mobile phones ring -> if the call is answered by
a mobile phone the person picking up the call needs to press 1 (or another
key on the phone) to answer the phone, if that key is not pressed all phones
keep ringing as being it an unanswered call
If it is also required to press the key on the SIP phones than that is
acceptable.

Is it possible? Where should I look? I know some systems use it.

Regards, Mark