Exchanges that matter...

Nathan Stratton nathan at
Sun Dec 8 21:16:42 UTC 1996

On Sun, 8 Dec 1996, Stephen Stuart wrote:

> > 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.

Ah, if I have a FDDI connection into MAE-East I cant do full duplex unless
they enable it, it now is disabled.

> 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).

Well, because when I talked to MFS they said they would don't turn on full
duplex modem, I got the same thing from PAIX.

> >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? 

No, I turn it on, so far all the NAPs I have turned it off. If MFS and
PAIX wants to turn it on then great.

Nathan Stratton		  CEO, NetRail, Inc.    Tracking the future today!
Phone   (703)524-4800                          NetRail, Inc.
Fax     (703)534-5033                          2007 N. 15 St. Suite 5
Email   sales at                      Arlington, Va. 22201
"Therefore do not worry about tomorrow, for tomorrow will worry about 
itself. Each day has enough trouble of its own."               Matthew 6:34

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