Home network bottlenecks

[Dotan Cohen]

I have two computers on a home network connected via D-Link router.
Both machines are running Kubuntu 9.04 with KDE 4.3 installed. The
desktop machine is always connected via ethernet cable to the router,
and the laptop will be either wired not wireless.

When the laptop is connected with the wired connection, file transfers
between the machines go at 6.0 - 6.5 MiB/s, slightly less than the 10
MiB/s that the hardware should support.

When the laptop is connected wirelessly, I get only about 400 KiB/s,
much less than the 10 MiB hardware limitation that I suspect of the
desktop's cheap NIC. This is with the laptop placed less than a meter
from the router, in full line of sight.

The router is a D-Link 320 which supports wireless protocols B and G:
http://www.ivory.co.il/product.asp?productid=3697&CatCode=581

The laptop is a Dell Inspiron but I do not know which wireless card it
has installed. Even if it is B only, surely it should be faster than
400 MiB/s, no?

How can I check where the bottleneck is? Thanks in advance.

-- 
Dotan Cohen

http://what-is-what.com
http://gibberish.co.il