ISDN Disconnects

[nandakesavan]

We are using ISDN Line to connect our brach office. The problem is line stays on only for couple of minutes.

isdn status on one side.

mid_ter_1604#show isdn status

The current ISDN Switchtype = basic-ni1

ISDN BRI0 interface

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 104, State = MULTIPLE_FRAME_ESTABLISHED

TEI = 113, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

2 Active Layer 3 Call(s)

Activated dsl 0 CCBs = 2

CCB:callid=8002, sapi=0, ces=1, B-chan=1

CCB:callid=2, sapi=0, ces=1, B-chan=2

Total Allocated ISDN CCBs = 2

mid_ter_1604#

I am also attaching the config files of both the routers. I appreciate your help.

Thanks

K7

[Richard Burts · Accepted solution]

Nanda

I believe that I see the problem. On router ter_mid_1604 I see that the Bri is configured with dialer-group 1 but there is no dialer-list in the config. The other router has both a dialer-group and dialer-list but this router is missing the dialer-list. If there is no dialer list, then the router has no way to identify "interesting" traffic for the ISDN. And if the router can not identify interesting traffic, then the router has no way to reset the inactivity timer and will terminate calls when the inactivity timer expires.

Many people tend to believe that only the calling router needs dialer-group and dialer-list since they are essential for initiating the call. But they also serve to reset the inactivity timer and if the answering router does not have dialer-group and dialer-list then it will have the symptoms you describe of terminating calls after a couple minutes (the inactivity timer defaults to 2 minutes).

So put a dialer list on router ter_mid_1604 and see if it does not work better.

HTH

Rick

[nandakesavan]

Rick,

Thanks a Lot for your help.I added the dialer list and it worked fine. I have one more question.

I did an online bandwidth test, it shows only 62kbps. It is supposed to be 128kbps leased line. I can see only one light is lit in bri 0 in the front panel of the router. What should I do to get 128kbps?

Thanks Again

k7

.

[sundar.palaniappan]

There are couple of ways you can get both b-channels to come up right away though I prefer the 2nd way. Configure them on both ends.

dialer load-threshold 1

OR

ppp multilink links minimum 2

HTH,

Sundar

[alsayed]

Hi

can i know how you did an online bandwidth test?

10xs

Ali

[nandakesavan]

http://www.bandwidthplace.com/speedtest/

[nandakesavan]

Sundar,

Thankyou for your response.

I got the following error. Is there anything I am doing wrong?

mid_ter_1604(config)#

mid_ter_1604(config)#interface bri 0

mid_ter_1604(config-if)#ppp multilink links minimum 2

^

% Invalid input detected at '^' marker.

Thanks Again,

k7

[sundar.palaniappan]

You might be running a older code and the command is slightly different.

Try 'ppp multilink min-links 2'. Or just type ppp ? and it will give you the supported options.

HTH,

Sundar

[nandakesavan]

I tried the following options,

bigs_ter_1604(config-if)#ppp ?

max-bad-auth

authentication Set PPP link Authentication method

bridge Enable ppp bridge translation

callback Set PPP link callback option

chap Set CHAP authentication parameters

compression Enable PPP Compression control negotiation

multilink Make interface multilink capable

negotiation-timeout Negotiation timeout period

pap Set PAP authentication parameters

reliable-link Use LAPB with PPP to provide a reliable link

use-tacacs Use TACACS to verify PPP Authentications

If I type ppp multilink ? , I do not get any options,

bigs_ter_1604(config-if)#ppp multilink ?

How do I proceed further?

Thanks

k7

[sundar.palaniappan]

This command was introduced in IOS version 11.3. You must be running a code older than that. So, use the dialer load-threshold 1 to activate the 2nd channel quickly.

HTH,

Sundar

[nandakesavan]

Yes, I noticed the version numbers are 11.1 and 11.2

I already have the following lines in my config files.

dialer hold-queue 5

dialer load-threshold 128

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

On the other side of the router, I have

dialer hold-queue 5

dialer load-threshold 1 either

Please see the attached config files in my earlier post. Do I still need to add dialer load-threshold 1 to activate the 2nd channel? I appreciate your help.

Thanks

k7

[sundar.palaniappan]

Set the threshold to 1 on both ends.

Send a few 100 pings across the link. You should see the router trying to bring up the 2nd b-channel. If you are still having problems, post the output of show isdn status, show dialer, debug dialer etc.

--Sundar

[nandakesavan]

After changing the threshold to 1, I pinged more than 100 times on both the direction and I reloaded both the routers and it didn't show the other channel. So I physically turned off and turned on both the routers and then both the channels were up. But they were up only for couple of minutes and I lost the connectivity between routers.

Then again I turned off and turned on the router, but this time only one channel is up.

Below are the debug outputs

mid_ter_1604#show isdn status

The current ISDN Switchtype = basic-ni1

ISDN BRI0 interface

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 72, State = MULTIPLE_FRAME_ESTABLISHED

TEI = 81, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

1 Active Layer 3 Call(s)

Activated dsl 0 CCBs = 1

CCB:callid=1, sapi=0, ces=1, B-chan=2

Total Allocated ISDN CCBs = 1

mid_ter_1604#

mid_ter_1604#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last called Last status

4989081 0 195 00:00:23 failed

4989080 0 195 00:00:23 failed

0 incoming call(s) have been screened.

BRI0: B-Channel 1

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

BRI0: B-Channel 2

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Time until disconnect 2099995 secs

Connected to 4989080 (ter_mid_1604)

mid_ter_1604#

mid_ter_1604#debug dialer

Dial on Demand debugging is on

mid_ter_1604#debug isdn q921

ISDN Q921 packets debugging is on

mid_ter_1604#debug isdn q931

ISDN Q931 packets debugging is on

mid_ter_1604#debug dialer

Dial on Demand debugging is on

ter_mid_1604#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last called Last status

6405006 0 102 01:57:52 failed

6405005 3 102 01:57:45 successful

0 incoming call(s) have been screened.

BRI0:1 - dialer type = ISDN

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Dialer state is physical layer up

Dial reason: ip (s=10.11.1.25, d=10.11.255.255)

Time until disconnect 2092885 secs

Current call connected 01:58:51

Connected to 6405005 (mid_ter_1604)

BRI0:2 - dialer type = ISDN

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Dialer state is call being disconnected

Other side of the router:

ter_mid_1604#show isdn status

The current ISDN Switchtype = basic-ni1

ISDN BRI0 interface

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 64, State = MULTIPLE_FRAME_ESTABLISHED

TEI = 73, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

1 Active Layer 3 Call(s)

Activated dsl 0 CCBs = 3

CCB:callid=0, sapi=0, ces=2, B-chan=0

CCB:callid=2, sapi=0, ces=1, B-chan=2

CCB:callid=80CF, sapi=0, ces=2, B-chan=1

Total Allocated ISDN CCBs = 3

ter_mid_1604#show dialer

BRI0 - dialer type = ISDN

Dial String Successes Failures Last called Last status

6405006 0 102 02:28:37 failed

6405005 3 102 02:28:30 successful

0 incoming call(s) have been screened.

BRI0:1 - dialer type = ISDN

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Dialer state is physical layer up

Dial reason: ip (s=10.11.1.25, d=10.11.255.255)

Time until disconnect 2091066 secs

Current call connected 02:29:05

Connected to 6405005 (mid_ter_1604)

BRI0:2 - dialer type = ISDN

Idle timer (2100000 secs), Fast idle timer (20 secs)

Wait for carrier (30 secs), Re-enable (15 secs)

Dialer state is call being disconnected

Any help is appreciated,

Thanks

k7

[sundar.palaniappan]

Based on the output you posted, appears your 2nd SPID (6405006) isn't working. Work with the Telco to troubleshoot.

HTH,

Sundar

[nandakesavan]

I called telco. It seems like no problem from their side.Thanks for your help.

k7