[asterisk-users] fail-over server

[Vieri]

Hi,

Suppose you have 2 identical Asterisk servers and 1 alias IP address that you assign to either one, according to system failures, etc.
Also suppose that all SIP clients register requests go to the alias IP address.

Imagine server1 fails and server2 gets the alias IP address. Correct me if I'm wrong but I would have to wait at least 60 seconds before most SIP clients re-register to server2 and that server2 knows that they are actually "on-line" so calls can be routed to them.

How can I minimize this time lapse? Can Asterisk "notify" all SIP clients in its sip.conf that they need to acknowledge being on-line or not (thus forcing re-registration in my scenario)?

Thanks,

Vieri