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New Member

ISDN BRI possibly not configured right.....

I am having some difficulty with an 802 router.

We recently got a new telco for isdn and something is strange The facts:

1. A 3com impact modem works fine on both the Old and New ISDN lines

2. The router works fine on the Old line

3. Router + new line = trouble.

trouble is layer 1 wont come up... I have tried using different switchtypes but the new telco says its national so ive been using basic-ni1. Layer 1 status seems to go back & forth between Deactiveated and Activating. I took a look at show controllers bri as well and there is a note that the telco is performing loopback testing. If this is correct then why can the 3com dial I am very confused. If smeone could please point me in a good direction to explore this further I would appreciate it.


Cisco Employee

Re: ISDN BRI possibly not configured right.....

Troubleshooting Layer 1 will be the best starting point for you..Here is the link which will guide you for that

After that Layer 2 and above

New Member

Re: ISDN BRI possibly not configured right.....

Thank you for giving me a good doc to start with.

I have finished the troubleshooting steps outlined here but I still have an issue. The Layer 1 status is sometimes ACTIVATING and sometimes DEACTIVATED So I ran the "sh Control Bri" command and it says that the CO is running a Loop-back test, if this was true than why can I dial with my external modem. Can I make the router ignore this supposed error message and bring the link up anyway?



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