Hi,
thanks for your help.
Yes, Rob, that is what I am looking for. This seems to be the same way, as it worked with ring groups with the chan_sip driver, isn't it? Because, that always worked quite well for me.
I'm going to try the dial option "c" next weekend. Hope it does what it should. Because a call, that isn't answered anywhere, of course should be a "missed call" - on every ringing endpoint.