[6458] in North American Network Operators' Group
Re: Exchanges that matter...
daemon@ATHENA.MIT.EDU (Stephen Stuart)
Sun Dec 8 13:35:36 1996
To: Nathan Stratton <nathan@netrail.net>
Cc: Joe Rhett <joe@navigist.com>, Sean Doran <smd@cesium.clock.org>,
nanog@merit.edu
In-Reply-To: Your message of Sun, 08 Dec 96 11:22:20 -0500.
<Pine.LNX.3.95.961208112133.9654A-100000@netrail.net>
Date: Sun, 08 Dec 96 10:23:30 -0800
From: Stephen Stuart <stuart@pa.dec.com>
> At the Atlanta-NAP we offer full duplex FDDI, why not try to get MFS to do
> it? Cisco now has a full duplex FDDI card, so you can do 200 Mbs into the
> NAP.
Every NAP with a GIGAswitch/FDDI offers full duplex FDDI; the MAEs,
Sprint, PAIX, and you. Buy a full-duplex-capable card, install it, and
you get full duplex. You, the NAP operator, do nothing; the devices
negotiate in and out of full duplex mode themselves.
I'm somewhat confused as to why you would say you offer full duplex
FDDI in a manner that implies no-one else does. If someone walked up
to your GIGAswitch/FDDI (or anyone's) with a full duplex line card,
they'd get full duplex unless you took some specific action to prevent
it (by, say, putting three stations on a ring), or if you disable it
in management (it comes enabled by default).
From Chapter 1 of the Big Book of GIGAswitch/FDDI (June 1993):
"Point-to-point links can operate in a full-duplex mode to increase
bandwidth and reduce latency. Using FDDI, simultaneous transmission
and reception in a point-to-point connection between two FDDI adapters
that support full-duplex communication can provide twice the raw
bandwidth of the data link. When a point-to-point link is created with
a station that can use full-duplex mode, the communication mode is
changed from token ring to full-duplex. No token is passed in
full-duplex mode. Configurations can automatically move in and out of
full-duplex mode as the opportunity (two stations on a ring, both
capable) becomes available, or unavailable. Full-duplex mode can be
disabled using MIB objects in version 2.7 of the DEC Vendor MIB."
Since you point it out as a specific offering, does that mean you turn
it off by default? Do you charge more for it?
Stephen
