Can you give me more details on what you mentioned as the best practice? Certainly! For your configuration, I would use this command, "dialer map ip 69.x.x.x name irim-max6k-alpha broadcast 5527100" instead of the dialer string command. It is the traditional way to configure BRI. It creates a static dialer map, where the dialer string is dynamic. I have occasionally seen problems with the dialer string command on the BRI interface. For the command, the IP address would be of the remote router. The "name" keyword is needed because you are using CHAP authentication. The "broadcast" keyword is only needed if you want to send broadcast or multicast traffic over the circuit (e.g., routing protocol). Thanks, Tom ... View more

I do not see a dialer-list command in your configuration. The backup interface command puts the BRI interface into Standby mode. If the command is removed or the Serial interface goes down (not admin down) then the BRI interface comes up. It does not dial, it only comes up. After the BRI interface comes up, you should see Layer 1 Active and Layer 2 MULTIPLE_FRAME_ESTABLISHED when you run the "show isdn status" command. You will need a dialer-list and interesting traffic to match the dialer-list to cause the BRI to dial. For example, "dialer-list 1 protocol ip permit" and "ping 69.x.x.x" (remote ISDN interface) will do. As a side note, a best practice is to use the dialer string with a dialer interface and a dialer map with the BRI interface. Dialer string will workon the BRI, but I have seen some issues with it occasionally. Thanks, Tom ... View more