[NTLUG:Discuss] Ethernet Switches

[Dan Carlson]

If it supports full-duplex, then it is a switch, not a hub.  Full-duplex
requires a non-shared point-to-point medium.  Hubs operate on a shared
medium, which is not capable of supporting full-duplex.  A switch does not
have to support  full-duplex, but most that are available today do.  Just
to confuse matters further, a switch is sometimes called a "switching hub",
or even a "bridge", depending on what reference you read!

The full-duplex mode was originally specified in the 802.3x-1997
supplement.  Subsequently the 802.3 spec was revised to incorporate most of
the supplements, and the discussion of full-duplex is now distributed
across various sections of the document.  In 802.3-2000 the basic
definition is given in section 1.1.1.2 on page 2.  After covering the basic
details it states:

"The most common configuration envisioned for full duplex operation
consists of a central bridge (also known as a switch) with a dedicated LAN
connecting each bridge port to a single device."

So if on the box it says it supports full-duplex, then it is a switch, not
a hub.

Dan Carlson

----- Original Message -----
From: "Travis Bell" <tjbell at usa.net>
To: <discuss at ntlug.org>
Sent: Monday, October 08, 2001 3:48 PM
Subject: Re: [NTLUG:Discuss] Ethernet Switches


> As interesting as it's been listening to the discussion of the technical
differences between a hub and a switch, it doesn't answer my original
question.  What I originally wanted to know is: What should I look for on
the product's box to be sure that the product inside is truly a switch and
not a hub?  I imagine it might have something to do with that
"802.<mumble>" comment that was made in a previous post.
>
> Thanks guys...it's been an interesting discussion.
>
> --
> Travis Bell  a.k.a.  MudPoet
> echo tjbexx at usa.nyz | tr xyz let
> ICQ: 6014042  -  AIM: MudPoet
> http://www.mudpoet.org
> _______________________________________________
> http://www.ntlug.org/mailman/listinfo/discuss
>