Network cable category wtf

[andtfoot]

I'm just doing a training thingie (Telecommunications) for work, and littered throughout it are... odd ways of describing things.

Is it just me or does questions 4 and 5 in the quiz not make sense? (It's also how it's described in the text)



Now a half-educated guess would have me say that gigabit Ethernet is transmitted at the same frequency, regardless of the cable used (let alone that it's not the cable itself that is transmitting  ).

[madires]

The correct answer for that bad Q4 is Cat 5e. Cat 5 is specified for 100MHz but not for GigE usage. The minimum required category for GigE is 5e. The trainer failed the test 

BTW: The clock rate for GigE is 125MHz for each TP. It's the same for FastEthernet. Second fail 

[Precipice]

Wikipedia thinks not -
http://en.wikipedia.org/wiki/Gigabit_Ethernet
down at the bottom, the difference between 1000BASE-T and 1000BASE-TX

[HackedFridgeMagnet]

Maybe
"What category of cable is characterised to 250Mhz." Might be a better question.

Most cables aren't intentionally transmitters.

[Fsck]

Maybe
"What category of cable is characterised to 250Mhz." Might be a better question.

Most cables aren't intentionally transmitters.

yeah, the wording makes the incorrect fundamental concepts worse.

[madires]

You can run GigE on Cat 5, but it's not remommended. The specs of Cat 5 are at the fringe of what GigE requires. Long cables or poor installation (too small bend radius and so on) will give you broken frames and a lot of FCS errors. Anyone involved in structured wiring of datacenters will tell you to use Cat 5e at least for GigE. Cat 5e has better specs and allows some abuse of the cable without causing too much trouble.

[Richard Crowley]

Just another example of being "copy edited" by non-technical people who likely "corrected" what they thought was "improper grammar".  Alas, you find this kind of problem in many places.  I call this "technical entropy."   

[Fsck]

You can run GigE on Cat 5, but it's not remommended. The specs of Cat 5 are at the fringe of what GigE requires. Long cables or poor installation (too small bend radius and so on) will give you broken frames and a lot of FCS errors. Anyone involved in structured wiring of datacenters will tell you to use Cat 5e at least for GigE. Cat 5e has better specs and allows some abuse of the cable without causing too much trouble.

same way that cat5e can work in clean environments in short runs for 10G.