Hint for more asterisk servers working together

Is it possible to configure more Asterisk servers to work together in such a way that there will be one central sip_buddies database and SIP client can register to any of these servers and it can receive and make calls using one assigned phone number?
I suppose there will be one “main” Asterisk server that receive all incomming calls and it redirects the call to the server where SIP client is registered and vice-versa, SIP client registered to any of these server wil be able to make call to other SIP clients in my “domain” of Asterisk servers and of course outgoing calls.

Can someone give me a hint how to configure this?

i could be wrong on this but last I remember it should work but for some reason didn’t. Not sure if it was fixed…

Have you looked at DUNDi and Realtime? Realtime allows all Asterisk to use one data source. DUNDi allows Asterisk’s to peer. I don’t have personal experience but conceptually these elements can do your job.

Well, with just Asterisk alone it wont work. Say you have 1 Realtime DB and about 4 Asterisk boxes all reading/writing to/from this DB. If a SIP agent registers on Asterisk A, then B, C and D wont know about this registration. This is why load balancing and failover is SOOO hard with Asterisk, it is a black art. Search on lists.digium.com for the issues about Load Balancing and Failover. One guy has a solution using DUNDI. Also look at using OpenSER in front of the Asterisk boxes, using the dispachter module