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New Member

ISDN backup problem

Hi everyone,

I have the following questions regarding ISDN BRI back up for Frame Relay:

1. Is the ISDN layer1 status "ACTIVE" if the primary link is up?

2. How can I know ISDN back up is working without unplug primary link?

3. How can test the ISDN link ?(i'm using loop test right now. Is there any other method?)

Thanks in advance.

8 REPLIES

Re: ISDN backup problem

Hi

You can do a manual isdn call using the cli

isdn test call interface calling number ..

This will trigger an isdn call which will be helpful to find out the L2 status of the line..

Once you do a test call then you can check out the same using show isdn status and show isdn active commands..

regds

Re: ISDN backup problem

Hi

To add to edwins post , you can also check by adding a route to the BRI or Dialer interface and make a ping to the ip , ISDN would just trigger to check the status.

Hope this helps

regards

vanesh k

Hall of Fame Super Silver

Re: ISDN backup problem

Man

Neither of the previous posts has answered your first question which is about ISDN layer 1 and whether it is active while the primary link is up. The answer is yes the ISDN layer 1 should be up and active whether the primary is up or is down.

Your second and third question both boil down to how to be able to test the ISDN. And we can not know how to really answer that without knowing a bit about how you have set up the backup of ISDN for primary link. If you have used the backup interface command and pointed directly to the BRI, then the BRI will be in a special standby state and there is no way to test without failing the primary (or removing the backup interface command). If you have used the backup interface and have pointed it at a dialer profile then that dialer profile is in standby state and can not be used but you can configure another dialer profile and can use the other dialer profile to test.

HTH

Rick

New Member

Re: ISDN backup problem

Hi all,

Thank you for your replies. Actually, we use dialer0 to back up Frame-Relay link. We also create Dialer10 for testing. Btw, I have performed these following:

1. show isdn status

--> ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

DEACTIVATED

Layer 2 Status:

Layer 2 NOT Activated

2. Ping to the IP of dialer10. --> unsuccessful

From my understanding, the problem is still at physical connection. So i need to check it again. Once it has been fixed, I can test ISDN using ping to dialer10.

Am I on the right track?

BTW, the "isdn call interface" is not available in this case.

Hall of Fame Super Silver

Re: ISDN backup problem

Man

If the layer 1 status is deactivated then there is a problem, probably at layer 1, that is preventing ISDN from doing anything. I would check all the cables and connections. If they look right then I would check the ISDN card. If that looks ok then I would check with the provider to verify that the circuit is still active and whether it is showing errors.

If you have configured dialer0 and have the frame relay interface with backup-interface dialer0 then the dialer0 interface is in the special state and will not function unless there is a failure of the frame relay. But dialer10 should work fine. So if you ping over dialer10 it should be a good test of the ISDN.

HTH

Rick

New Member

Re: ISDN backup problem

First of all, thanks all for your response. Currently, the problem hasn't been solved yet. It seems that the ISDN connection is not stable, this is what I got

Router#

Jan 11 20:46:32.103: %ISDN-6-LAYER2UP: Layer 2 for Interface BR0/0, TEI 98 changed to up

Router#

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 98, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 98, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 98, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Router#[A

% Unknown command or computer name, or unable to find computer address

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

ACTIVE

Layer 2 Status:

TEI = 98, Ces = 1, SAPI = 0, State = TIMER_RECOVERY

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

ACTIVE_ErrorInd

Layer 2 Status:

TEI = 98, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

Router#

Jan 11 20:46:55.265: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/0, TEI 98 changed to down

Router#show isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/0 interface

dsl 0, interface ISDN Switchtype = basic-net3

Layer 1 Status:

DEACTIVATED

Layer 2 Status:

Layer 2 NOT Activated

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 0 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

I found that if the U led on Elcon NT1 is solid green, layer 1 is ok, right?

Is there any ideas? Thanks.

Man.

Hall of Fame Super Silver

Re: ISDN backup problem

Man

The output that you posted seems to show that the ISDN came up and over the course of 32 seconds it was ok for a bit, then went to timer recovery, error indicated, and went down again. It still makes me think that there is some physical layer problem (or maybe possibly a layer 2 problem).

HTH

Rick

New Member

Re: ISDN backup problem

Hi Rick,

Thanks for your reply. I think it was layer 1 problem as I cannot make phone call by ISDN using TA & analog phone. I'll check with provider next Monday again.

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