I just got a notice from the FCC about their upcoming changes to 9-1-1 calls and rules. By next year anyone selling, renting, providing a Multi-Line Telephone Service (MLTS) which a PBX qualifies as. It also covers anyone that is providing outbound services to a MTLS system.
In a nut shell it states that all devices fixed (desk phones) or non-fixed (softphones/mobile clients) must be able to dial 911 and be routed to the proper PSAP along with valid address and call back number. There are even new rules as to what counts as an acceptable 911 notice/alert for the end users.
It looks like they are putting these new rules into place within the year so everyone will have plenty of time to get their stuff situated. I’m still trying to clarify a few things myself because hotels are mentioned a lot and the rules state that the full dispatched location must be presented which could mean that if there are office/rooms numbers (like a hotel or office complex) that those details should also be sent. Which could mean each office/room could require their own DID to present that information.
Here’s a couple of the PDFs I got linked too.