Active/Passive solution for 300 users, 2 sites Help needed!

Hi All,

I’d love to get some feedback from people on a project I’m just starting on.
We’re going to have 300 phones over two sites. The sites are connected by a 100meg link. There are more users (350) than devices so we’ll be using the log in/log out feature as well as the “deviceanduser” model to cope with that.
They are after a redundant solution and we have proposed roughly this.

We’ll put an asterisk box at each site. Both boxes will have identical configurations. All the phones at both sites will register with just the one server. If that server fails then they will re-register with the backup server. The call volume will be very low, as they are a college and teach most of the time. Maybe 25 simultaneous calls.

For T1 redundancy we’re using a T1 to IP/Ethernet converter from Redfone.

I’m trying to work out the best scenario for the failover on the servers.

a. Just configure a backup sip server on the 7940 phones
b. Run the two servers in HA config presenting a single virtual IP
c. Run a third server acting as a SIP proxy in front of the 2 asterisk servers

Any comments would be gratefully received and when all this is done I’ll post a full write up at

All the best,