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Issue with 836 not getting ISDN

Please note - the below is happening on german ISDN lines ...

We've occasionally had trouble at a couple customer sites with ISDN links ... with identical configs, we just can't get 836 routers to work on ISDN lines. Lines are directly at the NTBA, so no PBX or similar involved. When connecting the router to the line, it doesn't seem to be able to do _anything_ with the line. Debugging of Q921 packets may result in nothing, on other sites will show RX/TX packetes (though no connection possible). Replacing the router with a Bintec works fine, no trouble with getting ISDN to work.

Has anybody experienced something similar? Any idea?

Tnx, -gg

Reply to
Garry
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Hi,

did you check the switch-type? Should be basic-net3 in the case of an VERY old line it cout be 1tr6 (both should also be defined directly on the interface). Tried another IOS? Have you tried all of these:

c2620service#debu isdn ? L2-Sock-Proc ISDN L2 Socket Process packets events ISDN events q921 ISDN Q921 packets q931 ISDN Q931 packets

? Please post some debugs.

Andre

Reply to
Andre Janssen

Yes, Switch Type is configured to basic-net3, those lines are brand new, only EDSS1 ...

Same IOS works on other lines ...

Point seems to be that ISDN Layer1 seems to break down after a while ... Telekom has been on site at one place, messed around with the line, after which it worked - for a short while, then quit working ...

-gg

Reply to
Cisco Fan

Cisco Fan schrieb:

Just a guess: Is there another devices configured for the same MSN? Since my 836 is configured for a distinct MSN on the S0 bus problems are gone.

Reply to
Uli Link

No, 836 is the only device on the bus ...

Reply to
Cisco Fan

Garry, there have been some software bugs concerning the Cisco836 and ISDN. In Germany, T-Com uses two different brands of ISDN-switches, Siemens EWSD and Alcatel S12. Check to which of them those routers were connected. Although the bug is in the router, not in the ISDN switch, for some reasons it will occur much more frequently with the Alcatel switch than with the Siemens switch. Solution: software upgrade.

Regards, Axel

Garry wrote:

Reply to
Axel Gärtner

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