I have a client with a SDSL primary line and they are looking at some sort of redundancy in the case of SDSL failure. We've tried convincing them to go with a adsl backup but they're set on the isdn backup option.
They have a old cisco 1721 router that used to be used for an ISDN connection and want us to setup the Cisco 1721 with an sdsl wic as primary and have the isdn connection as a backup. And as the isdn will just be a pay per use service it would need to only dial if necessary.
So, I'm just wondering what would be my best option to trigger the isdn to dial if the sdsl interface goes down. I've used PBR before with failover E1 connections. Would that be an option here or is there a more simple option?
This question is pretty easy but is extremely urgent as they're hoping to put something in place this weekend so I'm going to go with 500 big ones!
Thanks in advance.