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New Member

ISDN debug output


I am giving here output of isdn debug command q931 and q921. but I am not in a position to find out what is the problem.

Is it related with serivce provides or with router. I am giving debug output at three different locations.

Pls see the attachment

Thanx in advance.



Re: ISDN debug output

this seems like a physical failure from the looks. (hardware, cabling....)

it could be a configuration error but i've never seen this type of isdn debug output with the typical configuration errors. (could be telco issue at their switch but haven't see this output from a telco idsn issue either)

clearly there is a problem with the router being able to allocate a B channel.

i see you get a TEI assigned. do you ever see MultiFrame Established? (show isdn status)

what version IOS?

please post your configuration if possible so we can see if anything wrong there.

New Member

Re: ISDN debug output

Dear Sir,

I will post configurations also.

Thanx for Support


New Member

Re: ISDN debug output

can u tell which IOS ur using or just send sh version output

New Member

Re: ISDN debug output

1)check the switch type hv to be basic-net3

check the IOS

also go through

New Member

Re: ISDN debug output

Hi there,

With the information that u gave, i could say that the B-Channel is not achieved.

Depending on the Master equipment, and the way this message appears (receive/send) this message, try to reset/re-configure the equipment that is sending that message.

We could be more helpful, if u could gave us the configuration of that BRI, and what type of equipment is on the remote end.

Best Regards,

Bruno Petr?nio

New Member

Re: ISDN debug output

hey man ..

this mean even ur isdn line is not working cant even find thte B-channels to do anything ..can u paste show isdn status ...this would help in troubleshoot ..see if layer is is active or not

rate if helps


Re: ISDN debug output

If you do a "Show ISDN Status" and look for "Multiple Frame Established" it will tell you if your Layer one is up ("Multi-Frame Established" = Layer 1 is up).

What kind of switch is the provider telling you they're using?

Have you verified the SPIDs? (or if you even need them)

Get some more output and post it (sh isdn status, sh ver, sh run (sanitized))


New Member

Re: ISDN debug output

Layer2 - TEI Assigned : 127 -- > 89 OK

Layer3 - ISDN BR1/0 **ERROR**: host_disconnect_ack: Unfound B-channe

l on Disconnect_Ack call id 0x8102 (NOT OK)

Ask for the remote device to check the remote IDSN card/NT, your router is connected to.

Sometimes reseting the BRI device could solve the problem.

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