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hprieur
12-10-2008, 07:49 AM
Hello,

I have installed, more than a year, a Quadro ISDN connected to a PBX, an ITSP and PSTN :
PSTN0 : PBX
PSTN1 : PBX
PSTN2 : not use
PSTN3 : PSTN

The system works fine for months when we got T303 error messages with ISDN ports connected to the PBX. A reboot of the Quadro and the system works for hours until the same issue.
We have already done 2 RMA since a year and today we got again this issue.

Any idea ?

Regards,
Herve

KSComs
12-10-2008, 06:15 PM
Just a thought... maybe there is a lot of noise on the ISDN circuit, or a temporary power failure or cable fault that causes this.
This is usually an ISDN carrier problem and one that will not go away...

Check the ISDN statistics for out of frame errors etc... check also in the events of the telephone system which will give indications of the times...
Then pass it back to the carrier for them to fix.

Regards

Kevin

artur_s
12-11-2008, 01:50 AM
Hello,

T303 errors means - on outgoing calls ISDN L3 does not receive any answer from ISDN L2.
This may happen in case of ISDN L1/L2 connection problem with carrier.
ISDN L2 logs(or systemlogs) with developer logs enabled will be more useful to find out the problem in such cases.

Artur

KSComs
12-11-2008, 04:55 AM
http://eu.sabotage.org/www/ITU/M/M3621e.pdf

that points to a document that might be useful.

Regards

Kevin