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Connection speed?

WE currently have 3500XL series of switches. A set in our computer room. A set in a remote closet,(on the same floor) and a set one floor up. this is all connected with a fiber connection. Each remote site is going to the computer room on separate fiber line. I believe that the fiber is going into a 1000BaseX GBIC at each end for both runs.

The connections from the computer room switches and the clost on the same floor are connecting at 100 MIPS, while at the remote site upsyairs everything is connecting at 10 MIPS.

One fiber line is older than the other. Is this a configuration problem, connection, or hardware?

We have tried to forced a connection at 100 MIPS, but no deal.




Re: Connection speed?

I would probably start by cleaning the fiber connectors on all the jumpers, and the optical jacks that each of them mate to.

Most folks do remember to clean the cable ends, but neglect to clean the recepticles (that are frequently left uncapped and exposed).

Also look for sharp bends in the cable, kinks, crushes, knots, etc in the jumpers and plant cabling.

If you have or can rent an OTDR (Optical Time Domain Reflectometer) and / or Optical Power Meter do some measurements and post the results.

An OTDR will give you apparent cable length (if there's a break in the cable, the OTDR will report the length as shorter than it should be).

The OPM will tell you how much signal (from a calibrated source) is getting through, or it will tell you what the actual signal level (from an uncalibrated source, like a GBIC) is.

Test in both directions on both fibers. A diagonal fracture of the fiber will act like a beam splitter and (usually) significantly reduce the power levels.

You can try switching / swapping GBICs as well, if one has a weak transmitter or deaf receiver the problem should travel with the GBIC.

That's it for me for now....

Good Luck


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