Problem to establish ISDN connection between 2 CISCO routers

[kongenkoo]

I have problem to esteblish conection between CISCO 4000 (12.0) and CISCO 801 (12.1) via ISDN line.

Both routers are configured using "standard working configuration" which we used for remote connection to our customers. But unfortunetely we have problem with last connection.

Configuration of our CISCO 4000 router:

hostname sllh4m

!

interface BRI0

no ip address

no ip directed-broadcast

encapsulation ppp

dialer pool-member 30

isdn switch-type basic-net3

no fair-queue

no cdp enable

end

!

interface Dialer2

ip address 10.8.10.102 255.255.255.192

no ip directed-broadcast

encapsulation ppp

dialer remote-name test801

dialer string 00111222333

dialer load-threshold 100 either

dialer pool 30

dialer-group 2

no fair-queue

no cdp enable

end

And customer CISCO 801 configuration:

hostname test801

!

interface BRI0

no ip address

encapsulation ppp

dialer pool-member 30

isdn switch-type basic-net3

!

interface Dialer2

ip address 10.8.10.101 255.255.255.192

encapsulation ppp

dialer remote-name sllh4m

dialer pool 30

dialer string 09999991

dialer load-threshold 100 either

dialer-group 2

no fair-queue

no cdp enable

!

See attachment for debbug output from our sllh4m router.

[Kevin Dorrell]

Are you using ppp authentication chap on this connection? I don't see it in the configs, but test801 seems to be requesting it in the LCP. If so, it needs to be configured on the dialer profile interface as welll as on the physical interface on both sides.

Kevin Dorrell

Luxembourg

[kongenkoo]

Hi Kevin,

on both routers there is no CHAP configure. I see that I attached older debbug file when CHAP was configured.

Please see new attachement.

For me the problem is:

BRI:1 LCP: TIMEout: State ACKsent

Regards

Martin Kral

[Kevin Dorrell]

Martin,

Are you saying that you have other clients that work correctly with this configuration? If so, maybe there is something I don't understand.

When the called end receives the call, it has to have some information that binds the physical channel into the dialer profile. That is, there must be something on the incoming call that says "I am so-and-so, so this call is part of Dialer n". Usually that is the CHAP username, but it is also possible to do it with the incoming dialed or dialing number if your switchboard provides it. Either way, it has to be configured: ppp authentication chap or dialer caller, or dialer called.

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a00800c6c62.html#wp1018848

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a008008000e.html#wp1120901

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a008008000e.html#wp1023505

Kevin.Dorrell

Luxembourg

[kongenkoo]

Kevin,

we're using ppp authentication chap and also I tried it for this customer. But to make troubleshooting easier I removed it because as I know it has to work without authentication.

As I can see Level1 connection is established between routers and on Level2 PPP fails because of LCP is let say down.

Here you can see output from customers router console:

1y16w: %DIALER-6-BIND: Interface BR0:1 bound to profile Di2

1y16w: %LINK-3-UPDOWN: Interface BRI0:1, changed state to up

1y16w: %ISDN-6-CONNECT: Interface BRI0:1 is now connected to 09999991

1y16w: %DIALER-6-UNBIND: Interface BR0:1 unbound from profile Di2

1y16w: %ISDN-6-DISCONNECT: Interface BRI0:1 disconnected from

09999991 , call lasted 24 seconds

1y16w: %LINK-3-UPDOWN: Interface BRI0:1, changed state to down

1y16w: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0, TEI 65 changed to

down

[Kevin Dorrell]

Martin,

Sorry, from the configurations you provided in the first posting, I still don't understand how the test801 router is binding the call on Bri0:1 into profile Dialer2. What information is it using to determine that the incoming call pertains to Dialer2?

Authentication usually provides this information as well as validating the caller. However, if you say that it normally works without authentication, then there must be some other information in the call that identifies it as Dialer2.

Perhaps it would be useful to see the full debug on test801 during the call. I'm sure that the called router will tell us more than the calling router.

Kevin Dorrell

Luxembourg