Don't have one I can try this on, so could someone supply the answer
please?

If you have a SIP-based service from a remote Asterisk server, and set
Call Forward, Always to a mobile (say). Where does the 'forward' take
place?
Are you sending instructions back to the server, which then does the
divert at that end until told otherwise, or does the call actually come
into the phone, and back out again?

What I would like to achieve, is to have an IP-based phone in the
Office, divert to mobile whilst travelling. Take the phone to a remote
office, and be able to take the divert/forward off from there.

TIA,
Philip Partridge

One idea might be to create a call queue in Asterisk just for Phil's
use, where calls to Phil's DDI go. That way, you can log in to the
queue from wherever location you have a SIP phone and take calls on
your DDI. And set it up so that when you're not logged in to your
queue, calls get diverted to your mobile. That way the Asterisk server
will know instantly that you're not available as soon as you log out of
your personal queue, and won't try to make a connection to a phone that
isn't there.

As for how the divert actually works; Something tells me mobile telcos
aren't quite progressive enough yet to offer you an IAX interface to
your mobile, so you'd have to route the divert to your mobile over the
PSTN, the same way you'd place calls to any other PSTN number. It would
make most sense to set the divert up on the Asterisk server rather than
on a SIP phone.

alexd

One idea might be to create a call queue in Asterisk just for Phil's
use, where calls to Phil's DDI go. That way, you can log in to the
queue from wherever location you have a SIP phone and take calls on
your DDI. And set it up so that when you're not logged in to your
queue, calls get diverted to your mobile. That way the Asterisk server
will know instantly that you're not available as soon as you log out of
your personal queue, and won't try to make a connection to a phone that
isn't there.

As for how the divert actually works; Something tells me mobile telcos
aren't quite progressive enough yet to offer you an IAX interface to
your mobile, so you'd have to route the divert to your mobile over the
PSTN, the same way you'd place calls to any other PSTN number. It would
make most sense to set the divert up on the Asterisk server rather than
on a SIP phone.

alexd