I am trying to work out a method of routing multiple inbound DIDs to one extension. I am ultimately trying to use VitalPBX as a middle man that a different PBX can register a trunk to. I am trying to do this because the internet at the external PBX is flaky and I would like to route the calls to cell phones when the extension is unregistered/unavailable. I have this working in a single DID scenario but in a multiple DID scenario I have no way of routing based on DID on the external PBX. My best guess is to have the to field in the sip invite be <did>@IP instead of <extension>@IP but do not know how to accomplish this.
If some could let me know how to do this or if I am going about it completely wrong it would be greatly appreciated.
Edit: used preformed text, as it was impossible to understand the difference. - mod