1000BaseT characteristics confusion

Jasiono

So I've been studying and going over things that I have trouble with, mainly port numbers and cables.

My two sources are exam cram and cbt nuggets.

I watched the cbt nuggets guy explain that 1000BaseT total distance/segment is 100m.
The exam cram pull out card states that it's 75m.

What is it?

Is the exam cram taking into effect the buffer you should give yourself on either end of the connection due to the connector and NIC? I read somewhere that the cable shouldn't be exactly 100m due to that.

What does the exam want as an answer, the 75 or 100?

ptilsen

I would imagine it's an error. The correct answer is 100m. The "buffer" for termination is certainly not 25m.

Jasiono

That's what I thought. 25m was too long.

ptilsen

I haven't used exam cram practices in a while, but certification material is notoriously error prone. I've sent in over 30 corrections for the Transcender 70-643 test, a good dozen for the Transcender 70-648 test, and probably a dozen each on the Preplogic Net+, Sec+, 70-290, and 70-291 tests.

If an answer doesn't strike true with your or even the wording seems wrong, do some independent research and get to the bottom of it. Either you'll identify a mistake -- which you can help correct -- or you'll learn something new. Good catch on this one.

veritas_libertas

Maybe they are getting it mixed up with 1000base-CX, which is indeed 25m. I'm thinking it's some confusion based on fiber or CX.

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