Redundant Asterisk systems for reliability

I’m looking for some ideas on configuring dual separate redundant Asterisk PBX systems such that if one of them fails, everything automatically and silently switches to the other one and continues operation.

This would have to work with POTS lines as well as IP-based connections, i.e. FXS and FXO ports on one box would have to be duplicated on the other box and their connections made in parallel.

If any of you have done this I’d appreciate hearing the details, otherwise I’ll see what I can come up with and report back.

Check the WIKI under High Availability.

For the ultimate solution you would probably put the POTS lines into a channel bank and connect the channel bank and any T1/E1 connections into a redFone switch and have access to any of the lines from any number of Asterisk boxes.