Asterisk for 1500 to 7000 users


Has anyone successfully implemented a large scale Asterisk deployment for between 1500 to 7000 users? Users are mainly virtual. Call capacity full ISDN (30 channels).

I am interested in feedback as to deployment, for example if other forum users would consider a single suitably high-powered server for such a deployment, or would instead consider splitting such a deployment across several servers? Redundancy and N+1 are not required.

Many thanks

I think if you plane to have more then 1000 - 2000 SIP users it is better to use Kamailio (SER) for registration of clients and load balancing, and Asterisk servers for processing of calls. I suppose 1 Asterisk server can handle around 100 - 200 simultaneous calls. And Kamailio server can handle up to 50 000 SIP clients.
In all our projects, where we plane to have more clients - we use Kamailio for registration and load balancing.