There are two methods that are obvious to terminate calls into mobile (GSM) networks in North America:
From my cell phone, I can just dial internal extensions (e.g. I can dial 0137720 on my cell phone, and my desk phone rings). This would appear to be
Just to give you a .uk experience, I don't know the technical details of how this is implemented, but from a user's point of view: Outbound (enterprise-to-mobile): My desk phone extension is 01-37720. If someone on the corporate PBX calls 071-37720, that's routed to my cell phone. Full internal CLID works (so my cell phone shows the extension of the caller, rather than an external number) Inbound (mobile-to-enterprise): the most ugly hack on the part of the mobile carrier, as it matches on number length to determine if it's an "internal" or an "external" call. However, it does mean that my cell phone appears to be part of the corporate PBX. According to our Intranet, this gives 30% call savings. Hope this helps, Simon