[54635] in North American Network Operators' Group

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RE: fast ethernet limits

daemon@ATHENA.MIT.EDU (Kristian P. Jackson)
Fri Jan 10 15:27:14 2003

From: "Kristian P. Jackson" <kahuna@krisjackson.net>
To: "'Steve Rude'" <steve@rudedogg.com>, <nanog@merit.edu>
Date: Fri, 10 Jan 2003 15:24:21 -0500
In-Reply-To: <Pine.LNX.4.33.0301101156150.11598-100000@lamb.coreis.net>
Errors-To: owner-nanog-outgoing@merit.edu


Steve, 

	What type medium are you using? If it is normal Cat5/6 then the
limitation is 100 meters for total distance and as you approach that
limit the signal degrades. That said, 100baseFX can run for 400 meters
due to the fact that it is fiber, both are part of the fast Ethernet
specification though. A repeater would boost signal, but perhaps a
switch in there might not be a bad idea, segment the 27 floors into
VLANs, reduce overall traffic traveling between floors and eliminate the
27 floor run.

Hope this helps,
Kristian P. Jackson

-----Original Message-----
From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of
Steve Rude
Sent: Friday, January 10, 2003 3:01 PM
To: nanog@merit.edu
Subject: fast ethernet limits


Hi NANOG,

Could someone please help me with a fast ethernet problem I am having.
We 
have a POP in a 27 floor building, and have a rj45 run from the the
bottom 
of the building (in the telco room) to the top of the building.  We have

cisco switches on either end and we are seeing about 5-20% packet loss
on 
the trunk.  

Are we running into a distance limitation of fast ethernet, or are we
suffering 
from another problem?  I read that 328 feet is the limitation of fast 
ethernet. Is there anything short of getting a repeater for the cable
run 
that I can do to boost the signal?

TIA for your help.

Ciao.

Steve Rude




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