Quick question on Category cable specs (regarding cable length)

[seepy83]

My understanding of the rules for Cat 5/5e/6/etc cabling is that the max distance between two devices (a switch and PC, for instance) is 100 meters. From previous posts on this board, people have said you are allowed 90 meters of solid copper cabling (obviously puched down to patch panel/keystone jacks) with 5 meters of stranded patch cable on each end.

If 1 end only requires 1 meter of patch cable (for instance, if a 24-port switch and patch panel are adjacent in a rack), are you allowed to use 9 meters on the other end?

Also, if you are not using any solid cable (if two devices are in the same room) can you use a 10 meter patch cable?

I'm guessing the answer to both of these is yes, but just want to make sure...

 

[RadiclDreamer]

It will work, you may get some errors on the line but yes it will work.

 

[seepy83]

Originally posted by: RadiclDreamer
It will work, you may get some errors on the line but yes it will work.

I'm not really concerned with whether or not it will "work". My question is whether or not it is in spec. I'm sure I can run a 50 meter patch cable, and it will "work" but I will get some errors on the line.

 

[JackMDS]

The issue is the Patch cables.

They are made of stranded conductors. Stranded conducdor start losing signal over length.

One simple solution is to get surface mounted Keystone and use them for the longest run with solid copper even if it is in the same room.

 

[imagoon]

It could be in spec. You need a tester to be sure. Like you mentioned with the 5-90-5 rule, most companies only test around that spec because they assume that shorter runs will run fine. Patch cables can be hard to keep in spec though. Once someone steps on it or wraps the cable to tightly etc it could fall out of spec.