ISDN backup for multiple T1 WAN links

[librizzs]

Does anyone know if there is a way to configure ISDN backup to be triggered only if ALL T1's in a multiple WAN link (NxT1) are down? This scenario could likely occur if one link was down for maintenance, for example. I am only familiar with setting up a single T1 link failure, and do not want ISDN engaged if one or more T1 links are still up.

[rais]

If all N T1s are going to a single destination, then you can use 'dialer watch'. Dialer watch looks for a route in your routing table. As soon as the route goes away, it can dial ISDN backup.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_configuration_guide_chapter09186a00800872ed.html

HTH.