Recently, we have decided to go with FreePBX throughout the company. So far we have 4 installations. Eventually, we will end up with over 100 installations. We don’t want to create rules on every installation with information on how to get to a particular extension on a certain server. What is the best practice for extension/route advertising?
That would become very unwieldy in 100 copies of FreePBX, I would suggest you just put a sip proxy before the PBI. I would further suggest kamailio to handle that routing.
There was and still is, DUNDI, that attempted that but it is pretty well dead now because it was too cumbersome to manage and wasn’t designed for easy extension routing.