ISDN Stuck in TEI_ASSIGNED

teodor.dobrev · ‎08-11-2006

Hi to all i have in a office,Cisco Router 1760 with VIC2-2BRI-NT/TE interface connected to Telco through ISDN BRI service.

ISDN Protocol is going up just normal.After the first call isdn layer 2 goes down and stucks in TEI_ASSIGNED state.Have you see something like that?

Any help is apreciated - by the way i contacted the telco but they turned out to be very rood and unsupportive wich is another problem:)

i will attach debugs from the first call after wich no further isdn communication is possible and also sh run.

teodorgeorgiev · ‎08-11-2006

From first sight looks like the remote switch "wants" to do TEI negotiation on a per call basis. After the link is idle for some time, they bring the L2 to inactive state.

Try using this command -->

isdn tei-negotiation first-call or

isdn tei-negotiation power-up

Or there might be some problem with the TEI negotiation.

run a q921 debug, not q931 and post it. It will show a lot.

teodor.dobrev · ‎08-12-2006

Hi,

i have tried this - it doesn't work either.

Q.921 is not saying anything different than q.921 is going down and it going to TEI_ASSIGNED.

The link is good no matter how much time it stays idle, but after the first call is made - it is going down, i clear the interface it is good untill the next first call:)

ISDN switch i am connecting to is verry old - unfortunately it will be verry hard to get any help from the other site's people - but i am trying.

teodorgeorgiev · ‎08-12-2006

If after clearing the ISDN interface the issue is fixed, then 90% this is a TEI negotiation issue. Set TEI negotiation to static on your side and consult with the PTT to do the same.

Set this command on the BRI interface, it will definitely do the job:

isdn static-tei 0

Btw, in no way the PSTN switch could be "very old". It is either Siemens EWSD or AXE-10. No idea for AXE, but on the Siemens of EWSD there are really a lot of features/options that could be applied to the ISDN link.

teodor.dobrev · ‎08-12-2006

I already did that to

set it to static-tei 0, didn't work.What is PTT?

P.S It is time to know each other (Ogi is always talking about you to me :) )

teodorgeorgiev · ‎08-12-2006

debug isdn q921

start it before trying to accomplish a call and 1-2min after the Layer 2 goes down disable it.

post the output. The answer to your trouble is inside.

teodor.dobrev · ‎08-18-2006

Hi,

this thing was outrageous :)

I eventualy changed the switch-type to basic-ni and it worked fine.The telco are keep teling me that it is euro-isdn though:)

So i lost a few days of crazy troubleshooting and changig ios and etc...

Thanks for the help

teodorgeorgiev · ‎08-18-2006

World would be a better place to live if everyone was working what he knows and understands at his best.

I am sure from these telco (ptt) guys would

come out good construction engineers, dentists, volleyball coaches, but they should definitely leave their current job if they use NI/NI2 in Europe =)