I am configure the 4 ports ISDN NM as a backup link of frame-relay in cisco 2610 router. Once the frame-relay disconnect, i need to bring up the four line together due of heavy traffic. Problem is, if one of the port get down or one of the line not active, then the remain ISDN port will not be activate as well.
Eg : If line of port 2 fail, then the router will able to bring up the line at port 3 only. The router will keep trying to bring up the port 2. It will hit error and stop there.