Ethernet question

[Ken Ambrose]

On Tue, 27 Aug 2002 pll at lanminds.com wrote:

> Ohhhhhh!  Okay, I get it.  So 100Mbit doesn't use 4 pair any more?
> Then why they heck are we still spending all that money on 8-strand
> cat 5?  Cut the prices in half and waste half the amount resources :)

"Any more" isn't quite right: it all depended on whose standard you used.
The -Tx folk never used four pair.  The handy part about four pairs is:

1) Under duress, you can split off another run.  Handy when someone
   -needs- a run in a place that's been built over.
2) Gigabit does use all four pairs, and it's getting -cheap-.  Heck:
   Netgear has a card, ~$80, which is fast, works with Linux (well...
   with the Red Hat kernel, at least -- the driver isn't in the stock
   2.4.18 kernel, as I found out to my distress).  The card also has
   a feature that, IMHO, is _LONG_ overdue as a standard across the
   board: it autodetects your send and receive pairs.  So, if you have
   a "null modem" cable, it figure it out.  Lastly, it works fine
   for 100/10 Mb/s, too.  Highly recommended if you're running RH,
   and I even saw some benchmarks -- one card, going for $300 or so,
   beat it by some 20%; it was just about at the top as compared to
   the Intel and 3Com cards, though.  Scope it out at
   http://www.netgear.com/product_view.asp?xrp=1&yrp=1&zrp=118 .  They
   also have a 64-bit card for ~$120; see
   http://www.netgear.com/product_view.asp?xrp=1&yrp=1&zrp=94

$.02,

-Ken