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
> 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!
Perhaps you should talk to them again. Steve Feldman (MFS) has said
multiple times that FFDT is enabled on the MFS Gigaswitches. At the last
NANOG, he suggested people try out the 'new' feature implemented by Cisco
and send him feedback. As Stephen Stuart (PAIX) pointed out you have to
disable the feature as it's enabled by default.
Perhaps a better theory on the reason certain providers are de-emphasizing
their MAE/NAP connections is that they're concerned about people
"stealing" bandwidth on their links via 3rd party routing.
-jh-