On Thu, 16 Nov 2006 02:09:31 -0500, "David" <this@is.invalid> wrote in
<abydnf2TRMkxk8HYnZ2dnUVZ_vqdnZ2d@comcast.com>:

>"John Navas" <spamfilter0@navasgroup.com> wrote in message news:2oaml2d6rte609f7qol4q8eln6r8hkbjvn@4ax.com...
>
>> A likely cause of your problem is RF interference. (Check your error
>> rate.) Perhaps a neighbor is using the same channel and hiding the
>> SSID, so you haven't noticed. ;)

It's also a good idea to turn off *all* security and restore everything
to *default* values when troubleshooting (including turning SSID
broadcast ON). I've seen a number of cases where something like SSID
hiding resulted in performance problems. Then configure to your taste,
and track resulting changes.

>Both the Intel software and Netstumbler report the presence of my own
>wireless router when it is using SSID hiding so I wonder if the latter is a
>possibility. According to NetStumbler all the other devices around here
>(one or two of which are on my channel) are coming in at -85 dBm or
>worse while mine is around -17 dBM when testing here in my office.

Interference could be coming from many other possible sources. See wiki
below for a list of possible sources.

>In Intel Advanced Statistics->Statistics signal strength is -18dBm, the
>percent transmit errors stat is 0, and nothing else seems to be reflecting
>any wireless problems.

OK.

>FWIW, here is a summary of the Speakeasy download speed test results.

Also try <http://netspeed.stanford.edu/>, which I've found more reliable
than other test sites.

>The first is baseline (just through my Comcast cable modem), the next two
>include the Wireless Router in the path:
>
>Notebook<-- CM -->Speakeasy (16Mbps)
>Notebook<--switched-->WR<-- CM -->Speakeasy (16 Mbps)
>Notebook<--wireless-->WR<-- CM -->Speakeasy (7 Mbps)
>
>Next, I used iperf to exercise all paths through the router and eliminated
>my cable modem and the Internet from the picture. In these tests I used
>my notebook and desktop computers, with both being directly connected
>to the specified ports on the router:
>
>Notebook<--wireless-->WR<--uplink-->Desktop (19.6 Mbps)
>Notebook<--wireless-->WR<--switched-->Desktop (25 Mbps)
>Notebook<--switched-->WR<--uplink-->Desktop (40 Mbps)
>Notebook<--switched-->WR<--switched-->Desktop (93.5 Mbps)

From these it seems the WR isn't playing nice with the CM with a
wireless client. Even though wired seems to work OK, check for a bad
WAN cable, connector, or (as Jeff suggested and I discounted in another
thread) NWay Autonegotiation <http://en.wikipedia.org/wiki/NWay> failure
(e.g., duplex mismatch <http://en.wikipedia.org/wiki/Duplex_mismatch>).

>Assuming 25Mbps over TCP over a non-accelerated G only wireless
>connection is good, I'm inclined to think that my wireless connection is
>good and RF interference isn't really a problem. I've played with every
>Intel 3945 and WRT54GL setting I could think of and that didn't have
>any noticeable impact on performance in any of the above scenarios.
>I don't know what is going on, but one thing jumps out and that is the
>reduced throughput when traffic is moving through the uplink port.

A drop isn't unexpected, because the router only comes into play between
WAN (uplink) and LAN ports.

I personally wouldn't waste too much time on this -- I'd try another
wireless router; e.g., pick up a Buffalo at your local Best Buy that you
can return if it doesn't help.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_HowTo>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>