ISDN

[ali.asghar]

Is it possible to combine 3 Bri Interfaces (6 Channels) to come up at the same time when the primary link goes down. I know 2 Bri Channels on Bri interface can be combined through Multilink PPP, but has never done to combine 3 physical Bri ports as a one link.

Is it possible?

2) What is the best way to bring the ISDN up for static routes. I guess I have no choice except creating static routes with the higher adminstrative distance.

I am talking about atleast monitoring 15 to 20 static routes. Do I have anyother choices.

Thanks,

[lgijssel]

Hello Ali,

This should be possible. Multilink PPP should even work over links on different routers. This is not an easy config to build, but in the configuration guide you should find what you are looking for under multilink PPP.

2: To my best knowledge, floating static routes are indeed the best solution for this situation.

Regards,

Leo

[ali.asghar]

Thanks ! one more question though.

Usually, one DN is enough to make a call, and allow both channels to be up by configuring "PPP Multilink with Dialer Load-thershold" command.

The ISDN provider, however gives you 2 DN for each B channel. Could you shed some light when to use both DNs. I usually find issues with assigning both DN to Bri interface.

Thanks,

[lgijssel]

Ideally, you should arrange for a group-number. That is: all three bri's answer the same DN.

It is not so that a particular DN is attached to a fixed B-channel. The DN's are meant to make it possible that multiple devices can be attaced to one ISDN line without interfering with eachother. Each device only answers calls to his assigned DN.

With Cisco, use the isdn answer command to use this feature.

Regards,

Leo