Newsgroups: comp.unix.programmer,comp.os.linux.networking,alt.os.linux
Subject: Re: Max throughput of Ethernet
References: <[email protected]>
"Rick Goh"  writes:

> hi all, what is the max throughput of ethernet. 
> I'm told that at most, on a good day, the max throughput is only about 30%
> meaning:  a 100mpbs lan ~ at most 30mpbs ??

Those who claim 30% are either repeating old number or do not know
the whole picture. On shared media Ethernet, like coaxial cable
or twisted pair network with HUB in between, the throughput
is whole network in normal case is usually of around 30-50%
of the capacity depending on how many computers are in one
segment and what kind of traffic is going there.

In case of full-duplex ethernet point-to-point links
(for example 100 Mbit/s link between two computer or from
one computer to switch/router) is around 100% on both directions
(if you take out some protocol overhead, you get something like 90-95%)
Because you get same speed possible to operate at full speed
to both directions, the total theoretical capacity would be nearly
200% of the nominal speed capacity. Think this as 100% or 200% 
whatever direction you look at the direction-

Depending on the network configuratio of the Ethernet configuration,
you get either 30-50% or around 200% of the moninal speed of the Ethener
for the total data capacity (both uplink and downlink counted together).
If you are just downloading, then the speed you get is practically
30-50% or over 90% of the moninal speed.


-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/