ISDN WAN Connections

Basic Rate Interface (BRI)

This was set up in a lab enviroment using an Adtran Atlas 550 to simulate WAN connection. This will document configuring an ISDN BRI connection with dial-on-demand routing (DDO), RIP routing over ISDN, and B channel aggragation.

Configuring BRI

1. Basic Router Configuration
2. Configure the router to use the approiate ISDN switch types,
   • This configuration uses the basic-ni switch type. To learn about the other switch type go to ISDN Switch Types
   • Router(config)# isdn switch-type type
3. Use Dialer List to identifiy intresting traffic
   • Router(config)# dialer-list dialer-group-number protocol protocol-name permit | deny | list access-list-numeber
4. Configure BRI Interface with encapsulation and authentication settings
   • Router(config)# interface interface-number
   • Router(config-if)# ip address ip-address subnet-mask
   • Router(config-if)# encapsulation ppp
   • Router(config-if)# ppp authentication chap
5. Congigure a service profile identifier (SPID)
   • Router(config-if)# isdn spid spid-number local-dial-number
6. Set the Dialer Idle Timeout
   • The dialer idle timeout defualts to 120 seconds. It may need to be changed to a lower value to avoid excesive call charges.
   • Router(config-if)# dialer idle-timeout seconds
7. Associate the interface to the already created dialer-list
   • Router(config-if)# dialer-group dialer-group-number
8. Configure the Dialer Map
   • The dialer map tells the interface what to do with interesting traffic
   • You do not need to enable broadcasts if your routing protocol does not need broadcast.
   • The dial string is the destination telephone number.
   • Router(config-if)# dialer map protocol next-hop-address name hostname [broadcast] dial-string