Minimum 10Base100 Cable Length

I've scoured the Internet searching for the minimum 10Base100 UTP cable length, but there seems to be no consistency. Several sources state different lengths and include footnotes with different applications...

So, I have two network devices sitting one on top of the other. They are an HA cluster that are using a 10Base100 heartbeat. The RJ-45 jacks on the two devices are approximately two inches apart. I would like the heartbeat cable to be as short as possible and adhere to cabling standards, but I can't find any hard reference to any IEEE specs for my situation...

Can anyone help me justify a three inch heartbeat cable?


Reply to
Bob Holding
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there is an issue with crosstalk. A very short cable doesn't decouple the NEXT of the two connectors. You end up with 3 dB less NEXT. But this should be no problem for 10BaseT or 100BaseT (Fast Ethernet).


NEXT is Near End Crosstalk, generated by the connectors, cable contributes much less

"Bob Holding" schrieb im Newsbeitrag news:

Reply to
Thomas Beneken

I have in my hand such an interface crossover cables. Wire length about 8cm, and they ran 100baseTX full duplex without trouble at full speed (~12 MByte/s each direction). I also have made loopback plugs with 2cm total wire length.

-- Robert

Reply to
Robert Redelmeier

That may be true, but in terms of signal to noise ratio, there is more signal so that a little more noise shouldn't cause much of a problem.

There may be some fiber systems that will saturate the receiver if the cable is too short.

-- glen

Reply to
glen herrmannsfeldt Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.