isdn connection problem

[guw]

hello, i have 2 isdn router. If i initiate the connection from router A the connection works fine, if i initiate the connection from the router B i get no connection. i see in the log-file the bri-interface comes up, but the next second it goes down again. If i initiate from router B allways BRI0/0:2 comes up, on sucessfully connections initiated from router A, on router B the interface BRI0/0:1 comes up (for Layer1 aktivation i had to insert the command "isdn tei-negotiation first-call")

any idea ?

thank you, Walter

[Georg Pauwen]

Hello Walter,

which IOS versions are you running on your routers ?

Can you post the full configurations of the routers ?

Regards,

GP

[guw]

Dear GP....

here the requested informations...

best regards,

Walter

[Georg Pauwen]

Hello,

on your dialer 6 interface of your ISDN-PRI router the multilink feature is not enabled, whereas that is the case on the remote site router. Can you try and add the 'ppp multilink' command to your dialer 6 interface ?

interface Dialer6

description *** milano ***

ip unnumbered Loopback0

encapsulation ppp

dialer pool 1

dialer remote-name isdn-milano

dialer idle-timeout 90

dialer enable-timeout 5

dialer string xxx

dialer hold-queue 10

dialer-group 1

no cdp enable

--> ppp multilink

ppp authentication chap callin

Also, since your remote router is challenging the main router for CHAP authentication, you do not need the username of the remote router in the configuration of the main router:

username isdn-milano password 7 xxx --> not necessary

Regards,

GP

[guw]

Dear GP...

thank you for the info, i added the ppp multilink command, but there is the same behavier as before...

best regards,

Walter

[vcjones]

I assume Milano is the Router A and Heerbrugg is the Router B you refer to in your original message. The Milano dialer on Heerbrugg says to use CHAP while Milano is configured to use PAP. Calls coming into Heerbrugg work because the authentication is done by the PRI config (which accepts PAP or CHAP) before binding the call to the dialer.

Vincent C Jones

www.networkingunlimited.com

[guw]

Dear Vincent...

sorry the pap statement was only for tests, the original configuration is with chap...

regards, Walter

[vcjones]

Another simple explanation is that the line at B is not configured by the service provider to place calls to A. That is, it is configured to disable the ability to place outgoing toll calls or outgoing calls in general.

This should be visible if you do a "debug isdn events" and look up the call clearing code returned when B tries to dial out. You should do this debug anyway, just to find out where to look for the call rejection.

Good luck and good hunting.

Vincent C Jones

www.networkingunlimited.com