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New Member

ISDN woe: router dials, connects, disconnects after 2 - 4 secs repeatedly

I have a strange problem here, and I'd like to get an opinion on what might be the problem. Basically, I have two routers, a 2600 and a 3600, connected to each other using frame relay with ISDN as a backup. This config was setup by my predecessor, and as such looks like it may have once worked (but no one can assure me of this)... in recent times, we've had flaky line issues with the frame relay, and noticed that the ISDN line would dial from the 2600, connect to the 3600, and terminate after 2 seconds. This would repeat ad nauseum until the frame relay line came back up.

I'd like to get a resolution to this problem, and I'm not sure what is going wrong. After reading through many posts in this forum, I was unable to find a similar issue, but maybe I was looking hard not smart!

Here's the configs from both routers and the output of some debug commands. I'd be grateful for any suggestions as to how to fix this.

3600 router relevant config-

------------------------------------

version 12.2

hostname Kenny

username gw-c2621-1 password 7 XXXXXXXXXX

isdn switch-type basic-ni

call rsvp-sync

!

interface BRI2/0

description ISDN link

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

dialer idle-timeout 300

dialer load-threshold 200 either

dialer-group 1

isdn switch-type basic-ni

no cdp enable

ppp authentication chap

ppp multilink

ppp multilink interleave

2600 router relevant config-

------------------------------------

version 12.2

hostname Kyle

username sj-c3662-1 password 7 XXXXXXXXX

isdn switch-type basic-ni

call rsvp-sync

!

interface BRI0/0

ip address 192.168.1.2 255.255.255.252

encapsulation ppp

dialer idle-timeout 300

dialer map ip 192.168.1.1 broadcast 18005551212

dialer load-threshold 200 either

dialer-group 1

isdn switch-type basic-ni

no cdp enable

ppp authentication chap

ppp multilink

ppp multilink interleave

!

access-list 101 deny ospf any any

access-list 101 permit ip any any

dialer-list 1 protocol ip list 101

There is more to the config on the frame relay interface and such, but irrelevant to this config, unless someone disagrees...

And here are the debug command outputs from the 3600 side when I initiate a manual call from the 2600:

2600:

--------

Kyle#isdn test call interface brI 0/0 14084339642 speed 56

3600:

--------

Kenny#debug isdn q931

ISDN Q931 packets debugging is on

Kenny#debug dialer

Dial on demand events debugging is on

Kenny#debug ppp negotiation

PPP protocol negotiation debugging is on

Kenny#debug ppp authentication

PPP authentication debugging is on

ISDN BR2/0: RX <- SETUP pd = 8 callref = 0x4C

Bearer Capability i = 0x8890218F

Channel ID i = 0x89

Signal i = 0x40 - Alerting on - pattern 0

Called Party Number i = 0xC1, '5551212', Plan:ISDN,Type:Subscriber(local)

ISDN BR2/0: Event: Received a DATA call from <unknown> on B1 at 56 Kb/s

ISDN BR2/0: Event: Accepting the call id 0xA90

%LINK-3-UPDOWN: Interface BRI2/0:1, changed state to up

BR2/0:1 PPP: Treating connection as a callin

BR2/0:1 PPP: Phase is ESTABLISHING, Passive Open [0 sess, 1 load]

BR2/0:1 LCP: State is Listen

ISDN BR2/0: TX -> CALL_PROC pd = 8 callref = 0xCC

Channel ID i = 0x89

ISDN BR2/0: TX -> CONNECT pd = 8 callref = 0xCC

Channel ID i = 0x89

ISDN BR2/0: RX <- CONNECT_ACK pd = 8 callref = 0x4C

Channel ID i = 0x89

Signal i = 0x4F - Alerting off

BR2/0:1 LCP: TIMEout: State Listen

BR2/0:1 LCP: O CONFREQ [Listen] id 223 len 27

BR2/0:1 LCP: AuthProto CHAP (0x0305C22305)

BR2/0:1 LCP: MagicNumber 0x556F8A69 (0x0506556F8A69)

BR2/0:1 LCP: MRRU 1524 (0x110405F4)

BR2/0:1 LCP: EndpointDisc 1 Kenny (0x1308014B656E6E79)

BR2/0:1 LCP: I CONFACK [REQsent] id 223 len 27

BR2/0:1 LCP: AuthProto CHAP (0x0305C22305)

BR2/0:1 LCP: MagicNumber 0x556F8A69 (0x0506556F8A69)

BR2/0:1 LCP: MRRU 1524 (0x110405F4)

BR2/0:1 LCP: EndpointDisc 1 Kenny (0x1308014B656E6E79)

BR2/0:1 LCP: I CONFREQ [ACKrcvd] id 2 len 26

Oct 1 19:30:27.696 PDT: BR2/0:1 LCP: AuthProto CHAP (0x0305C22305)

Oct 1 19:30:27.696 PDT: BR2/0:1 LCP: MagicNumber 0x04A45CA9 (0x050604A45CA9)

Oct 1 19:30:27.696 PDT: BR2/0:1 LCP: MRRU 1524 (0x110405F4)

Oct 1 19:30:27.696 PDT: BR2/0:1 LCP: EndpointDisc 1 Kyle (0x1307014B796C65)

BR2/0:1 LCP: O CONFACK [ACKrcvd] id 2 len 26

BR2/0:1 LCP: AuthProto CHAP (0x0305C22305)

BR2/0:1 LCP: MagicNumber 0x04A45CA9 (0x050604A45CA9)

BR2/0:1 LCP: MRRU 1524 (0x110405F4)

BR2/0:1 LCP: EndpointDisc 1 Kyle (0x1307014B796C65)

BR2/0:1 LCP: State is Open

BR2/0:1 PPP: Phase is AUTHENTICATING, by both [0 sess, 1 load]

Oct 1 19:30:27.696 PDT: BR2/0:1 CHAP: O CHALLENGE id 222 len 26 from "Kenny"

BR2/0:1 CHAP: I CHALLENGE id 1 len 25 from "Kyle"

BR2/0:1 CHAP: Waiting for peer to authenticate first

BR2/0:1 LCP: I TERMREQ [Open] id 3 len 4

BR2/0:1 LCP: O TERMACK [Open] id 3 len 4

BR2/0:1 PPP: Phase is TERMINATING [0 sess, 1 load]

ISDN BR2/0: RX <- DISCONNECT pd = 8 callref = 0x4C

Cause i = 0x8090 - Normal call clearing

%ISDN-6-CONNECT: Interface BRI2/0:1 is now connected to Kyle

%ISDN-6-DISCONNECT: Interface BRI2/0:1 disconnected from Kyle, call lasted 4 seconds

%LINK-3-UPDOWN: Interface BRI2/0:1, changed state to down

BR2/0:1 LCP: State is Closed

BR2/0:1 PPP: Phase is DOWN [0 sess, 1 load]

BR2/0:1 DDR: disconnecting call

ISDN BR2/0: TX -> RELEASE pd = 8 callref = 0xCC

ISDN BR2/0: RX <- RELEASE_COMP pd = 8 callref = 0x4C

And the logs that are sent to syslog look like this:

------------------------------------------------------------------

Oct 1 19:01:54 Kenny 31077: Oct 1 19:01:54.707 PDT: %ISDN-6-CONNECT: Interface BRI2/0:1 is now connected to Kyle

Oct 1 19:01:55 Kenny 31078: Oct 1 19:01:54.707 PDT: %ISDN-6-DISCONNECT: Interface BRI2/0:1 disconnected from Kyle, call lasted 2 seconds

Oct 1 19:30:28 Kenny 31083: Oct 1 19:30:28.920 PDT: %ISDN-6-CONNECT: Interface BRI2/0:1 is now connected to Kyle

Oct 1 19:30:29 Kenny 31084: Oct 1 19:30:28.920 PDT: %ISDN-6-DISCONNECT: Interface BRI2/0:1 disconnected from Kyle, call lasted 4 seconds

For obvious reasons, I've changed the IP addresses, phone numbers and passwords. Please let me know if anyone has any ideas or suggestions. I've tried using recent firmware, and both routers are on 12.2.12, and have had the same problem from 12.2.6 onward AFAIK.

Thank you for any assistance or comments.

---Maxx

2 REPLIES

Re: ISDN woe: router dials, connects, disconnects after 2 - 4 se

You might want to add 2 commands at each end..

at 3600 end

int bri 0/0

ppp chap hostname gw-c2621-1

ppp chap password xxxxxxxxxxxxx

at 2600 end

int bri 0/0

ppp chap hostname sj-c3662-1

ppp chap password xxxxxxxxxxxxx

This should work.

New Member

Re: ISDN woe: router dials, connects, disconnects after 2 - 4 se

Thank you. Exactly what was needed.

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