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RE: CSU/DSU help topic posted 01/19/2001
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Well, line code violations would refer to excessive zeros. Your line coding
is B8ZS which stands for Bipolar-8 Zero Substitution. Bipolar in this case
means that the zero is represented with no voltage, while one will be
represented with some voltage, either positive or negative. Positive and
negative will be alternated, so one may be represented by (let's say) -5
volts, next one will be represented by +5 volts. However, if there are too
many zeros in a row, timing sync may be lost. So in B8ZS if there are 8
zeros in a row, they will be replaced with a pattern containing two
violations. Meaning, there will be two +5 volts and two -5 volts in a row,
instead of them alternating. If 8 zeros are not received as such pattern,
the device will record line code violations.
Path code violation is CRC-6 error for ESF. 
Slip seconds indicate number of seconds when the timing was not exactly
right and it led to loss of data.
Framing lost seconds indicate how many seconds during which the out of frame
error was detected at least once. 
Line error seconds are indicating seconds in which at least one violation
occured, whether line or path.
Degraded minutes refer to minutes during which there were so many errored
seconds, i am not sure of the number.
Bursty err seconds and severely err seconds indicate seconds when a certain
number of errors occured, once again I don't recall the numbers.
Unavailable seconds indicate how many seconds the signal was not available

Hope that helps? I'd suggest getting the circuit tested.

Michael Yurchenko
CCIE# 6695, CCDP, CCNP ATM Specialist, MCSE
Customer Support Engineer - 2

-----Original Message-----
From: Maljure, Sanjay [mailto:smaljure@xxxxxxxxx]
Sent: Friday, January 19, 2001 10:40 AM
To: ccielab@xxxxxxxxxxxxxx
Subject: CSU/DSU help topic

Hi everyone.....
I was wondering if anybody could help me out with the following output.
This is a 1750 router with a built-in CSU/DSU
I notice several errors being displayed. What do these various terms
mean? What is the difference between 'Line Code Violations' and 'Path
Code Violations'? Any help would be appreciated. Thanks for your time.

Router#show service-module
Module type is T1/fractional
    Hardware revision is 0.104, Software revision is 0.2,
    Image checksum is 0xED22BEC5, Protocol revision is 0.1
Receiver has no alarms.
Framing is ESF, Line Code is B8ZS, Current clock source is line,
Fraction has 4 timeslots (64 Kbits/sec each), Net bandwidth is 256
Last module self-test (done at startup): Passed
Last clearing of alarm counters 23:40:06
    loss of signal        :    7, last occurred 02:25:42
    loss of frame         :    9, last occurred 02:25:42
    AIS alarm             :    0,
    Remote alarm          :    0,
    Module access errors  :    0,
Total Data (last 94 15 minute intervals):
    2357 Line Code Violations, 2295 Path Code Violations
    2 Slip Secs, 917 Fr Loss Secs, 732 Line Err Secs, 0 Degraded Mins
    3 Errored Secs, 0 Bursty Err Secs, 1 Severely Err Secs, 916 Unavail
Data in current interval (430 seconds elapsed):
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail

Sanjay Maljure
CCIE# 6286
Enterprise Systems Consultant
Ciber, Inc.

Tel - 732.225.1700 
Fax - 732.225.1973

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