Devices and Users roaming between branch offices

I’m not sure if the is the appropriate forum for this, please advise if it should go elsewhere.

I have an interesting use case for a client that has two locations: the Main HQ location and a remote location that is actually part of a travelling road show. Every couple of months when the road show has setup shop in the new town, the entire corporate office is relocated to the travelling show site. Currently phones follow users through a complicated and manual configuration of follow-me and extension rewriting through IAX trunks.

I have to believe that Users and Devices mode is a better way to do this, I’m just not sure how the two FreePBX systems will share the users…

What I envision is a much simpler system where Site 1 maintains the Users (identified by extension number), DIDs, and Devices in the 1xxx range. Site 2 should have IAX trunk setup to the Main site and maintains devices in the 2xxx range. I want users to be able to sign out of their device in the 1xxx range, travel to the new site and sign in to the 2xxx device. Voicemail and DID needs to follow the user when then move between sites.

The main reason to not just do this over a single PBX is that connectivity can at times be spotty for the travelling road show. In that case backup routes have to be able to flow through a temporary but dedicated PRI on location.

a) Is this even possible?
b) If so, how do you maintain users across the PBXs?
c) If not, what direction should I take for the use case?

Your scenario begs for a real sip proxy, it would then be trivial.

So you suggest SIP Proxy rather than IAX trunk between locations? I’m not sure I follow.

I do, Asterisk is a back-to-back user agent, a proxy is a proxy, use the proxy for calls from your asteri, the Proxy is then the arbiter of where all calls come and go from without the necessity of maintaining a persistent but changing trunk, it is trivial to re route calls to from and between your asteri and your VSP’s.