Ascend Archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: (ASCEND) max6k 100Mb FD?
> > > Does anyone know offhand if any special configuration is required to
> > > get a MAX 6000 into 100Mb full duplex mode? Yes, the MAX is going
> > > into a 100Mb switch that can do full duplex.
> >
> > Is that a good idea anyway? My understanding is that FDX Ethernet
> > can actually DECREASE performance on very busy wires from excessive
> > collisions, retries, and lost packets.
> Huh?? That's the point of full-duplex, eliminate collisions.
I thought I remembered reading something about that in the Novell
list...Here's the message:
/** begin quoted message **/
Subject: Re: ....full duplex servers....
From: Joe Doupnik <JRD@CC.USU.EDU>
Date: 1998/05/13
Message-ID: <01IWZCV3ELPUAM493Q@cc.usu.edu>
Newsgroups: bit.listserv.novell
>Good morning, several times in the recent past there have been
>posting about implementing full duplex NICs in servers. Some folks
>on the list have written that this is a very bad practice......I have
>a full duplex, 100MB, card in a Compaq server(Compaq NIC too)
>connected to a Cisco 10/100 switch that seems to be running just
>fine. What is the problem, real or potential with this setup?
>Thanks....JWS.
--------
We've discussed this at length previously, but here again is
the obvious. How does a transmitter know when to shutup because a
wire is busy? FDX lacks the feedback to tell it. Frames will be lost,
"the network is slow" phone calls happen.
Switches/routers in series between transmitter and receiver
can buffer some frames, but only some and you don't know how many
(because some are in use from other traffic).
FDX does not double throughput, in can markedly reduce
throughput (because of lost frames). Unless you can demonstrate no
problems and a strong need then turn it off.
Joe D.
/** end quoted message **/
Danny Williams
Caldwell Trust Company
Venice, Florida USA
mailto:danny@ctrust.com
http://www.ctrust.com
++ Ascend Users Mailing List ++
To unsubscribe: send unsubscribe to ascend-users-request@bungi.com
To get FAQ'd: <http://www.nealis.net/ascend/faq>
Follow-Ups:
References: