I appreciated that this is a bit of a general question but…if I had a SIP enabled mobile phone on a WLAN, is it possible to forward an inbound call via SIP to an Asterisk PBX? eg when someone calls the mobile, I’d like Asterisk to answer.
Obviously a lot depends on the phone etc and generally you’d work it the other way round but is it fairly standard…with the right phone?
That’s something you’re going to have to ask your mobile carrier. The answer’s likely to be no, though.
If you’re setting a call forward directly on the phone itself, then the carrier’s going to have to then decide to setup a SIP call an send it over to Asterisk. I’m not aware of any mobile provider that offers this kind of service. I’m also not aware of any mobile phone that has a built-in interface for setting call forwarding rules.
Your best bet is to do something of the reverse. Invoke some number portability and direct your mobile’s number instead to a provider that offers SIP and PSTN services. Direct the VoIP-capable provider to send your number to either your SIP device or the PSTN (thus on to your mobile device) depending on whatever forwarding rulsets they allow. Alternatively, use Asterisk to perform the forwarding rules for you - but you’re still going to be using that provider for receiving and making calls from / to the PSTN in the first place.