Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

DSL with ISDN backup

Need some help on configuring ISDN backup for a DSL connection.

Cisco 1700 series with an ADSL WIC and a BRI WIC. The DSL is configured and working ok as a Dialer profile connected to the ATM interface. There is a default route to the dialer interface which is NAT'ed.

Any ideas or working configs on how I implement IDSN backup?

Thanks in advance.

Cisco Employee

Re: DSL with ISDN backup

Its tricky to design the backup scheme for DSL connection using isdn...Router need to know "some way" to determine that the dsl line went down...Here are the facts in your case.

1)Dialer interface will not go down at all so can't "backup interface" scheme on that interface

2)No routing protocol so can't use "dialer watch" for the routing update.

So, You can only use the following command "backup interface bri0" under the "interface atm0"..Which makes bri available only when the atm interface went down..But that tracks layer 1 issues only, so there are no way to achive a backup based on layer 3 issues over dsl/atm line.

There is a feature request CSCds88143 to address these scenario..Its not solved yet..Talk to your cisco rep.. to push it..

CreatePlease to create content