Thanks for your tip!
I have never used queues before - just tested them a few years ago. I don't think a queue will do the job for me. It only supports one announcement that is played to the caller when in the queue and one, when pulled out. They also had the problem, that a queue didn't support the "SIP answered elsewhere", when a call was anserwed, showing a missed call on the other phones. But, as I said, I don't know queues an my experience with them lays back some years. Perhaps you could explain me, how to set them up to work like I need.
I need ringing for 70 seconds, if all my extensions are available -> if nobody answers the call (i.e. not at home) I need a specific announcement for that situation.
I need an IVR, if one of my phones is in use, so that the caller knows just that -> he then should have the opportunity to decide between the described options.
In Microsoft Excel I would handle this with an If-Function If(RingGroup01=busy;goto IVR_busy;Dial RingGroup01)... But we aren't with Excel... 