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. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Multilink PPP with ISDN modems.

Currenly I have a Cisco 3640 with a E1 PRI. Dial in single channel works great. As soon as I try as a dial in client to do Multilink it fails the whole call. From my Windows 2000 DUN account I specify MSCHAP 128K. this does not seem to work. I have " PPP multilink" configured on the Dialer Interface. Finally is it possible to have the 3640 dial the isdn user back home?


Re: Multilink PPP with ISDN modems.

To troubleshoot any MPPP problems, you will have to enable some debug, after ensuring that you are running recent IOS code. You should have a look at

debug ppp neg

debug dialer

You want to confirm that MPPP is negotiated during the LCP phase, that authentication passes, and that IPCP is correctly negotiated (for the first call only, the second call should not).

The 3640 (or any router, really) can callback; there are solutions using ISDN or PPP:

New Member

Re: Multilink PPP with ISDN modems.

Thank you.

It turned out to be a problem with the clients ISDN modems. They were testing with a Motorola BitSurfer. We tested with a Duxbury.