BASIC NETWORKING-CAT 3 CABLE SPECS

7255carl

Hi guys, i was just hoping someone out there could just clarify something for me, i am revising for my core hardware exam on the 21st, and i was looking over the networking area when i noticed something in the technotes that differed from what i read in the mike meyers all-in-one book. The technotes say:

Cat.3 Data rates up to 4 Mbps in TokenRing networks, 10 Mbps in Ethernet networks, bandwidth of 16 MHz.

but the mike meyers book quotes Cat.3 with speeds of up to 16Mbps, have i missed something here???

thanks in advance for any help

carl

Plantwiz

7255carl wrote:

The technotes say:

Cat.3 Data rates up to 4 Mbps in TokenRing networks, 10 Mbps in Ethernet networks, bandwidth of 16 MHz.

Correct

but the mike meyers book quotes Cat.3 with speeds of up to 16Mbps, have i missed something here???

thanks in advance for any help

carl

You may wish to check the Errata.
http://www.totalsem.com/support/errata/index.php?book=pass_aplus_1



Though it's not likely a typo, but a misunderstanding or poor explanation.
16Mbps isn't the same as 16MHz



Data vs. Frequency (Voice)

http://www.epanorama.net/documents/wiring/twistedpair.html

Cat 3: This cable type is characterized to 16 MHz and supports applications up to 10 Mbps. Applications may range from voice to 10BASE-T. This is a low performance cable rating which is dissapearing. This is nowadays the minimal requirement for good quality structured telephone cabling system. This is also known as ISO/IEC 11801 Class C cabling. This was the standard for UTP performance as late as 1988. The FCC recently changed the requirement for telephone inside wiring to minimum of Cat 3 due to crosstalk problems with nontwisted quad-four. CAT 3 is no longer recognized by TIA.

http://www.bytepile.com/cable_categories.php





So both are correct depending on how they are explained, but CAT3 is very commonly (or I should say WAS) run for office phones, etc.. It's covered, but for the A+ I wouldn't invest too much time on getting to the nuts and bolts of this....HOWEVER, at some point you will want to know so it's good you have ask the question.


HTH

7255carl

thank you very much for your help on this, much appreciated

carl