Palle Jensen <(E-Mail Removed)> hath wroth:
>I have tried so solve this in a danish group, but without succes, so
>now I am trying here.
Well, as long as you don't attach any cartoons, we're safe. Just
where did all those protesters find Danish flags to burn?
>My problem is that I don't think I get the best out of the wireless
>network here. I have a 2 mbit ADSL connection, and with the cable
>plugged in I receive approximately 220 KB/Sek. Very steady.
>
>With my Wireless connection I receive with about 170 KB/Sek. This is
>the fact for both the stationary and the laptop.
As Mark said, that's fairly close to normal. Let's play with the
numbers.
2Mbits/sec on an ADSL connection will yield about 1780Kbits/sec or
about 222KBytes/sec. That's what the online performance tests should
show. The 10-15% overhead is the "ATM cell tax" penalty for using
ridiculously small packets (53 byte packets with 48 bytes of data) to
move potentially huge IP packets (64KBytes). This sorta explains how
it works:
|
http://www.convergedigest.com/bp-ttp...p?ID=190&ctgy=
If you have PPPoE or PPPoA, you'll be at the high end of the "ATM cell
tax".
>I connect to a FTP directly at my ISP. There IS bandwith enough.
Numbers, not generalizations please. What bandwidth are you getting
with FTP from your ISP? Some ftp clients (i.e. Windoze 98SE and ME)
report wrong numbers for transfer statistics. Some Windoze FTP
applications (i.e. CuteFTP) seems to report ridiculously high numbers
because they seem to do a running average. If the initial value is
very high, later values will be affected. You can also see that in
the IE6 file transfers, that start out with spectacularly high
transfer rates and eventually slow down. If the files are too small,
they never reach a stable average and tend to be toward the high side.
Also, if you're measuring thruput, be sure to test both UDP (streaming
video) and TCP (file transfer). UDP does not require an
acknowledgement and therefore goes faster than TCP.
So much for the ADSL part of the puzzle. When you get to the wireless
end, you'll find that it's MUCH faster than your 2MBit/sec. No way
should the wireless be a limiting factor unless something is broken.
I've had the stupid ethernet cable drive me nuts. It was miswired but
worked well enough to establish a connection. However, the error rate
was very large and the thruput was terrible. Replacing the cable
instantly fixed the problem. Don't remind me that I was the one that
built the cable.
Your maximum wireless performance should follow this table:
|
http://en.wikibooks.org/wiki/FAQ_for...ance_and_Speed
Notice the wide variations in wireless thruput depending on how the
wireless router is setup. For example, a 54Mbit/sec wireless
association can yield 24.4Mbits/sec in thruput. However, if you
enable the 802.11b compatibility mode, the maximum thruput drops to
about 14.4Mbits/sec. However, at most speeds, your wireless will be
running MUCH faster than your ADSL connection, so it's not an issue.
>I have also tried to bring home my laptop from work with build in
>wireless (Intel). I have placed it just next to the AP, and did see
>the same behaviour.
Intel Proset had some problems with the speed going down to 1Mbit/sec
in the presence of interference, and never bothering to go back up
when the interference subsided. Upgrade to the latest version.
>The weird thing is: I have tried to make a file transfere directly
>from the stationary PC to the laptop. Here I can get 300 KB/Sek. So I
>see that the network CAN move the amount of data that it should.
Via wireless or wired? 2.4Mbits/sec is still rather slow for either a
wired or wireless connection.
>Here is what I've got:
>
>A router/AP point type WRT54GC firmware 1.03.0. I have an external
>antenna connected to optimize the connection.
>
>To this router/AP I have to units connected:
>
>1) A stationary PC with a Linksys PCI network adapter. Newest Driver
>available.
Model number of the Linksys PCI card.
Hardware version number of the PCI card.
Software version that you claim is the latest.
This is probably un-necessary for solving this problem, but if you ask
questions later, it's a good thing to describe the hardware exactly.
>2) A laptop computer with a PCMCIA network adapter from 3COM. Newest
>driver available.
Same as above. Need hardware model, hardware version, and driver
version. Model number of the laptop and exact operating system is
also helpful.
>Signal situation?
>
>The stationary PC has got Exellent coverage allmost constantly. The
>laptop is weaker. The PCMCIA card is not so effective I guess?
>Low <-> Good coverage.
Linksys PCI adapter has a decent antenna. The 3com PCMCIA card does
not. The difference is in the antenna.
>The system is set up like this.
>
>DHCP disabled.
>WPA-PSK TKIP encryption (HEX63)
>Mac filter (Yes I know it sucks)
>
>What have I tried?
>
>I downloaded "Network Stumbler" to see if any other networks were
>interfering on the same channels that I used.
Netstumbler will only find access points that broadcast their SSID. It
cannot find client radios or non-802.11 devices. Instead of looking
for interference, just try changing the channel (1, 6, or 11). If the
performance improves, then you have interference on the old channel.
If you really want to find sources of interference, you should either
use Kismet (under Linux) or a spectrum analyzer.
>I ended up finding
>pretty good signal/noise ratio on my channel 6.
Amazing. My war driving through Santa Cruz shows that about 75% of
the networks heard are on channel 6.
>Fine. But I have to
>mention that I live a place with aprroximately 10 wireless netwoks
>within range.
How far is the "range"? In general, a wireless network will not cause
problems unless it's very close, very strong, or someone is using a
power amplifier.
>I am running out of ideas? Where can I tweak/test/whatever to get my
>network in shape?
I don't think you can. The only numbers I can find wrong is the
relatively slow 2.4Mbits/sec transfer rate. However, I have no idea
how you are testing this, so even that may be correct.
>Thank you in advance..!
Incidentally, your English is quite good.
--
Jeff Liebermann
(E-Mail Removed)
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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