To forward traffic across the ISDN link, you configure static routes in each of the routers. The suggested
routing method is static routes. Keep the following in mind when creating static routes:
All participating routers must have static routes defining all routes of known networks.
Default routing can be used if the network is a stub network.
An example of static routing with ISDN follows:
RouterA(config)#ip route 172.16.50.0 255.255.255.0 172.16.60.2
RouterA(config)#ip route 172.16.60.2 255.255.255.255 bri0
What this does is tell the router how to get to network 172.16.50.0, which is through
172.16.60.2. The second line tells the router how to get to host address 172.16.60.2 and to send
traffic out the BRI0 interface.