[NTLUG:Discuss] File transfer speeds

[Stephen Klein]

Here's something to check

Based on past experience from a long time ago, sometimes the switchport
and station's network card don't properly negotiate
full-dulplex/half-duplex.  If both aren't configured the same, it can
really screw with your throughput.  I don't know how "smart" your switch
is (the one I used to have you could telnet into it and adjust things,
get stats, etc...), but hopefully there is a way to check if the
fullduplex option is turned on or not for a particular port.

One inditcator that this may be the problem is to check the collision
stats in a utility like ifconifg (Linux) or whatever that command line
util was in windows (3Com's driver software has a similar feature if 
it's installed).

You can check the full/half duplex status of a stations network adapter
with "mii-tool -v" (if installed on your system) in Linux.  In windows,
you'll have to use whatever software was supplied by the card vendor.

If the network adapter is in half-duplex mode, and you are seeing a high
number of collisions and/or frame-errors, then it's possible that the
switch port is set to full-duplex.  It's hard to give a good rule of
thumb on what a sufficiently large number of collisions to indicate a
problem, since all of this depends on traffic patterns on your network
and collisions are a normal occurance for (half-duplex)ethernet.

For full-duplex, there should be no collisions reported on either the
stations's network adapter, or on the switch port.

Keep in mind, this is only a "possible" scenario.

Good luck,
Stephen



Courtney Grimland wrote:
> 
> What kinds of things can I do to increase the file transfer speeds on my
> home LAN?  I have a simple gateway router, a 5-port 10/100 switch, and 4
> computers in the LAN.  File transfers between computers seem to run
> around 500 Kb/s (kilobits).  There's no other traffic on the network
> here.  Most of the computers are Windows, and one runs Linux.  Can
> anything be tweaked?  How do I identify bottlenecks?  Or is 500 Kb/s
> reasonable?
> 
>                                      /-Win98 box (mine)
>                 Linux       10/100  /- Win98 box (roommate's)
> Cable Modem --- Gateway --- 5-port  -- Linux box (mine)
>                 Router      Switch  \- Win XP Laptop (roommate's)
> 
> --
> Good judgement comes from experience. Experience comes from bad
> judgement.
> 
> _______________________________________________
> http://www.ntlug.org/mailman/listinfo/discuss