Input errors on Serial line

stephen.stack · ‎07-17-2008

Hi guys,

Hope you can help. Am getting lots of input errors on both serial lines of a multilink setup.

Example:

5 minute output rate 127000 bits/sec, 24 packets/sec

131927962 packets input, 4255877724 bytes, 0 no buffer

Received 0 broadcasts, 523 runts, 6 giants, 0 throttles

25473 input errors, 25473 CRC, 1341 frame, 799 overrun, 0 ignored, 1729 abort

61849324 packets output, 1063406327 bytes, 0 underruns

0 output errors, 0 collisions, 237 interface resets

0 output buffer failures, 0 output buffers swapped out

8 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

This is only since 10 am this morning (about 6 hours)

Any ideas - telco want to come out an take line down to test. i'll try to avoid that if i can.

Regards

Stephen

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paolo bevilacqua · ‎07-17-2008

Have them test and fix as one of the circuits is most likely defective. You shoudl look at the individual interface stats to tell which one.

If you have it, "show controller T1 or E1" is also helpful.

stephen.stack · ‎07-17-2008

Just saw that the errors are only occuring on one side of the link i.e. one router - both interfaces!!

I would have thought that if there was a line error then perhaps the error would occur on both sides.

Telnet session have disconnected on me too.

Also, i am starting to think IOS problem.

IOS on Router with errors is v12.3-14.T7

IOS on stable router is V12.4-12.bin

Advice??

Thanks

Stephen

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paolo bevilacqua · ‎07-17-2008

As mentioned before, have telco test and fix.

Most likely both circuits are going through a same defective trunk.

stephen.stack · ‎07-17-2008

Ok. Will do. Gonna upgrade image all the same.

Thanks

Stephen

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joseph.derrick · ‎07-18-2008

Hi Stephen,

Input errors / CRC is an indication of clocking problem coming from your upstream network/service provider.

Please have your provider test the link, in most cases BER (bit error rate testing) should be performed.

Thanks,

k0rg

stephen.stack · ‎07-18-2008

You just reminded me of one of the fundamentals of Serial lines :)

We have the telco coming in to check it.

Thanks

Stephen

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bauti1428 · ‎07-18-2008

We also had the same issue before and we ran a loopback test and it was our PAT3 card that was causing the issue.