Growing Asterisk to a Cluster?

We all want to see asterisk succeed, but the true test would be to have an VoIP Carrier which would sell IAX trunks to businesses.

to do that, we would need a way to grow asterisk so its almost like a webserver or sorts (clustered and never down)…

the limitations i see have a lot to do with the bandwidth and CPU of a server. IF you had many SIP registration servers how can you let all the serevrs know where the SIP Phone is registered to?

if i wanted to take my design and support 1,000 users… how would i do it over multiple servers?

if i have (2) SIP Servers registering phones, the issue becomes, incoming calls and VM. IF a call rings in, and one of the SIP registration servers reports the SIP Account as “UNREACHABLE” then the call will go directly to Voicemail, when in reality the call should would still be ringing on Server (2) and the SIP Phone itself. this would result in many incoming calls going directly to VM when in fact the phone is registered…

off line questions: