[Asterisk-Users] Backup Proxy & Automatic Failover

[Adthrawn]

Hi,

I read in the Asterisk Whitepaper, that you can run two cloned servers, 
one as a primary, one as a backup, and have them automatically failover 
to the other unit when it crashes, or when you need to restart it. The 
primary application of course, would be ensuring calls can be made when 
frequent updates are being handled, or when an update must be restarted 
on a busy network.

The term TDM is banded around too, but from my knowledge, TDM is 
trunking (probably some clever acronym relating to trunking), and in 
Asterisk's case, using the IAX protocol. This leads me to the big 
question;

Is there anyway of shifting the load of one Asterisk server to another 
without breaking or loosing a call?

I know that with Survivable Routing (Cisco's big on this), the ISDN 
interface is actually a router; so the Proxy is just used to decide the 
destination and LCR functions, and then hands off to a router. This of 
course, if a Proxy went down, would just prevent new calls from being 
made, whilst existing calls can continue merrily - until someone 
switches the Router off, or corrupts the IOS settings :-)

At least with Routers, you can configure them to load manager 
effectively, but how do you backup and load manage Asterisk??

I using SIP, and will be using a bit of SCCP too, so any suggestions 
would be most grateful!!

Regards,
Ad.