Cisco LRE (LongRangeEthernet) Question

Hi folks,

We are trying to replace the SDSL link between two locations with Cisco LRE using WS-C2924-LRE-XL switch combined with 575 CPE.

In theory, the cabling should be suifficient enough to support LRE-5 link (~1km dry copper pair).

Unfortunately we cannot get link up, we are 100% sure that this is not error in cabling. Also, both devices communicate excellently in a lab condition.

Doing the "show controllers lre status link lo0/1" yelds

Port Link SNR RS Errs CPE-Tx Sw-AGC-Gain Interleaver PMD-S (dB) (dBm/Hz) (dB) Rx-Bsz Tx-Bsz

------ ---- ---- ----------- -------- ----------- -------------

----- Lo0/1 DOWN 0 0 0.0 0.0 16 0

0x84

The only visible difference seen between the unplugged port and port connected to the leased line is the changing state of "PMD-S". When Switch is not connected to the wall jack it shows 0x04, when connected it will display 0x84

Unfortunately the Cisco documentation is very dry about this field, it only claims that this is "Physical Media Device Status field used for Diagnostics".

Does anyone knows what the codes in this field mean?

Are there any other useful diagnostics and troubleshooting procedures we could perform to find our the reason for not receiving the signal?

Best Regards

Kirill

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Reply to
Kirill Ponazdyr
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Kirill Ponazdyr

To my mind this demonstrates that there is indeed a cabling issue.

Still I know nothing of LRE, maybe it uses the cable differently.

Google for [802.3ah pmd status] says:

formatting link

There seem to be two possibly relevant sections but both agree:

You appear to have

4 lossOfSignal - one or more PMIs in the aggregation group indicate Loss of Signal 8 snrMgnRemoteDefect(7), -- Remote SNR Margin Violation

i.e. A cable fault.

I am doing a LOT of guessing here however I can find no inconsistencies with the view that it is most likely a cable fault.

Reply to
AnyBody43

Reply to
Larry Jones

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