Strange ISDN q921 messages

Unanswered Question
Oct 23rd, 2009


Sometimes one of the BRI lines gets this q921 messages:

ISDN BR0/2/1 Q921: L2_EstablishDataLink: sending SABME

ISDN BR0/2/1 Q921: User TX -> RRf sapi=0 tei=123 nr=2

ISDN BR0/2/1 Q921: User TX -> SABMEp sapi=0 tei=123

ISDN BR0/2/1 Q921: User RX <- SABMEp sapi=0 tei=123

ISDN BR0/2/1 **ERROR**: L2_AdvanceVA: TX_ack_queue empty

This is already weird, but what I don't understand is the SABME message being received.

Anyone seen this, or knows what it might be?



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virverma Fri, 10/23/2009 - 10:31

Indicates that a supplementary service requested by the user cannot be provided by the

network. So this points to a TELCO issue and not BRI issue


This symptom is observed when a cable is pulled out and put back


Enter the shutdown command followed

by the no shutdown command on the affected BRI interface


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