The 1/e myth, was Re: [e2e] TCP Local Area Normal behaviour? any

[Noel Chiappa]

    > From: Cannara <cannara at attglobal.net>

    > seeing how CSMA/CD is superior to any token-passing system,

You really don't want to get into this.

In any event, it's kind of OBE, since most "CSMA/CD" systems these days are
anything but. Rather, they are usually actually hosts connected directly to a
bunch of switches, the whole kit-n-kaboodle linked together by point-point
links, all of which happen to use an access protocol that looks like
CSMA/CD. The latter being picked, of course, rather than something designed
for the purpose, since that was the dominant market technology at the time the
whole concept of "LAN based on inert transmission medium" became another dusty
page of computing history (along with rotationally optimizing assemblers,
etc), and it was easier to just adopt that, rather than have to replace all
the host interfaces.

<Irony_mode>
By the way, what is this "full-duplex" stuff people keep talking about?
I've never heard of a CSMA/CD network that supported full-duplex
operation.
</Irony_mode>

Anyone out there actually still have an Ethernet which actually is a long
coax cable with hosts hooked to it via transceivers? No, I didn't think
so...

    > the spike in token's heart is not just cost per node, but that the
    > crossover moves to higher access rates as nodes are added, meaning
    > that CSMA/CD becomes better, relatively, as LAN segments have more
    > nodes.

Your model seems to leave out a few factors which weigh against real
CSMA/CD (not the ersatz simalcrum people are using these days, see
above), such as network physical size. Gee, what a shock - you obviously
not having any axe to grind one way or another between the two
technologies.

	Noel