Say we have four IP phones in the office, and two phone numbers coming into asterisk XXXXXXXX671 and XXXXXXXX672, along any available zap channel out of 4 zap channels in total. 671 goes to one specific IP phone, and 672 calls the other three in a certain order.
Is there a way you can have any of the other three phones dial an extension so that, should 671 call the first IP phone and no one is near that phone to answer it, the incoming call along the zap channel should dial their phone instead?