Wireless considerably faster one way than the other

Acer Travelmate laptop with built-in Intel 2200GB 802.11b/g wireless
network adaptor, XP Pro.
Netgear ME102 802.11b Access Point, plugged into network hub.
2 more desktop machines plugged into the hub, both Win 2k, it's a 100Mb
network.
The Access Point is approximately 3 inches away from the laptop.

I'm experiencing really bad network throughput at the laptop end, but
have discovered that copying a large file from the laptop to one of the
desktop machines is fast - the problem seems to be only when
transmitting data TO the laptop. I get all sorts of network errors,
including disconnections. Signal strength on the laptop is a full set
of green bars when I look at the connection status, "excellent" when I
hover over the tray icon.

I downloaded QCheck, installed it on a desktop machine and the laptop.
When I run a throughput test at the laptop, sending from the laptop to
a desktop machine with 100kb packet size, I get roughly 5 to 6 Mbps,
which as I understand is as good as you can expect from 802.11b.
However, when I run the test from a desktop machine to the laptop, I
get around 30 kbps. Yep, kilobytes per second. And that's when it
works, most of the time the test fails - it only works reliably when I
reduce the packet size down to, say 5kb, then it shows a throughput of
about 1 Mbps.

Anyone have any idea what could be causing this? I've tried all
possible channel settings, and combinations of all other settings I can
see.

On 15 Jun 2006 13:35:06 -0700, "Dave Brown" <(E-Mail Removed)>
wrote in <(E-Mail Removed) om>:

>Acer Travelmate laptop with built-in Intel 2200GB 802.11b/g wireless
>network adaptor, XP Pro.
>Netgear ME102 802.11b Access Point, plugged into network hub.
>2 more desktop machines plugged into the hub, both Win 2k, it's a 100Mb
>network.
>The Access Point is approximately 3 inches away from the laptop.

That close may result in signal overloading in the radios.

>I'm experiencing really bad network throughput at the laptop end, but
>have discovered that copying a large file from the laptop to one of the
>desktop machines is fast - the problem seems to be only when
>transmitting data TO the laptop. I get all sorts of network errors,
>including disconnections. Signal strength on the laptop is a full set
>of green bars when I look at the connection status, "excellent" when I
>hover over the tray icon.
>
>I downloaded QCheck, installed it on a desktop machine and the laptop.
>When I run a throughput test at the laptop, sending from the laptop to
>a desktop machine with 100kb packet size, I get roughly 5 to 6 Mbps,
>which as I understand is as good as you can expect from 802.11b.
>However, when I run the test from a desktop machine to the laptop, I
>get around 30 kbps. Yep, kilobytes per second. And that's when it
>works, most of the time the test fails - it only works reliably when I
>reduce the packet size down to, say 5kb, then it shows a throughput of
>about 1 Mbps.
>
>Anyone have any idea what could be causing this? I've tried all
>possible channel settings, and combinations of all other settings I can
>see.

--
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_How_To>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

John Navas wrote:
> >The Access Point is approximately 3 inches away from the laptop.
>
> That close may result in signal overloading in the radios.

No, the reason it's that close is because I wanted to rule out distance
as a factor. They were originally about 30 feet apart.

On 16 Jun 2006 03:22:49 -0700, "Dave Brown" <(E-Mail Removed)>
wrote in <(E-Mail Removed) .com>:

>John Navas wrote:
>> >The Access Point is approximately 3 inches away from the laptop.
>>
>> That close may result in signal overloading in the radios.
>
>No, the reason it's that close is because I wanted to rule out distance
>as a factor. They were originally about 30 feet apart.

3" is too close.

--
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_How_To>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

John Navas wrote:
> 3" is too close.

Thanks John, but I'm getting the same results regardless of the
distance.

Regards,
Dave

On 15 Jun 2006 13:35:06 -0700, "Dave Brown" <(E-Mail Removed)>
wrote in <(E-Mail Removed) om>:

>Acer Travelmate laptop with built-in Intel 2200GB 802.11b/g wireless
>network adaptor, XP Pro.
>Netgear ME102 802.11b Access Point, plugged into network hub.
>2 more desktop machines plugged into the hub, both Win 2k, it's a 100Mb
>network.
>The Access Point is approximately 3 inches away from the laptop.
>
>I'm experiencing really bad network throughput at the laptop end, but
>have discovered that copying a large file from the laptop to one of the
>desktop machines is fast - the problem seems to be only when
>transmitting data TO the laptop. I get all sorts of network errors,
>including disconnections. Signal strength on the laptop is a full set
>of green bars when I look at the connection status, "excellent" when I
>hover over the tray icon.
>
>I downloaded QCheck, installed it on a desktop machine and the laptop.
>When I run a throughput test at the laptop, sending from the laptop to
>a desktop machine with 100kb packet size, I get roughly 5 to 6 Mbps,
>which as I understand is as good as you can expect from 802.11b.
>However, when I run the test from a desktop machine to the laptop, I
>get around 30 kbps. Yep, kilobytes per second. And that's when it
>works, most of the time the test fails - it only works reliably when I
>reduce the packet size down to, say 5kb, then it shows a throughput of
>about 1 Mbps.
>
>Anyone have any idea what could be causing this? I've tried all
>possible channel settings, and combinations of all other settings I can
>see.

1. Restore all settings to default values.
2. Don't use huge packets, which increases the cost of errors.
3. Make sure the ME102 has the latest firmware.
4. Use the latest Intel reference drivers and software for the 2200BG.
5. Move the wireless units at least a few feet apart.
6. Try testing with:
(a) Iperf <http://dast.nlanr.net/Projects/Iperf/>.
(b) Netio <http://freshmeat.net/projects/netio/>
7. Check the Intel statistics after transmissions.

--
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_How_To>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

"Dave Brown" <(E-Mail Removed)> hath wroth:

>Acer Travelmate laptop with built-in Intel 2200GB 802.11b/g wireless
>network adaptor, XP Pro.
>Netgear ME102 802.11b Access Point, plugged into network hub.

Is the ME102 running the Netgear firmware, or has someone installed
firmware from a DWL-900AP+ or WAP11?

>2 more desktop machines plugged into the hub, both Win 2k, it's a 100Mb
>network.
>The Access Point is approximately 3 inches away from the laptop.

Too close. The receivers will overload at that distance. There are
also some timing problems that appear at such a short distance. I'm
not sure if there's a real minimum distance, but methinks about 12" or
more is safe.

>I'm experiencing really bad network throughput at the laptop end, but
>have discovered that copying a large file from the laptop to one of the
>desktop machines is fast - the problem seems to be only when
>transmitting data TO the laptop. I get all sorts of network errors,
>including disconnections. Signal strength on the laptop is a full set
>of green bars when I look at the connection status, "excellent" when I
>hover over the tray icon.

Yep, been there. I've seen this when the 10baseT-HDX (half duplex)
interface on the access point ends up with a different protocol than
your network hub or switch. In particular, with a 10/100 hub or one
of the Netgear FS-xxx series 10/100baseT switches. This does not
cause disconnects, so that's probably not the problem.

If you're using a 10/100 hub (not switch), I would certainly want to
try using a 10baseT only hub, or a 10/100baseT switch, as the buffers
in the dual speed hubs are always a problem. Going from 10 -> 100 is
not a problem because the buffer can be emptied faster than the 10
port can fill it. However, going from 100 to 10 requires that flow
control and buffering work overtime. That's the way you get
assymetrical performance.

>I downloaded QCheck, installed it on a desktop machine and the laptop.
>When I run a throughput test at the laptop, sending from the laptop to
>a desktop machine with 100kb packet size, I get roughly 5 to 6 Mbps,
>which as I understand is as good as you can expect from 802.11b.

Maximum theoretical speed at 10Mbits/sec is 7.1Mbits/sec for UDP and
5.9Mbits/sec TCP. Most benchmark tests use file transfers which are
TCP. You're going as fast as 802.11b will go.

>However, when I run the test from a desktop machine to the laptop, I
>get around 30 kbps. Yep, kilobytes per second. And that's when it
>works, most of the time the test fails - it only works reliably when I
>reduce the packet size down to, say 5kb, then it shows a throughput of
>about 1 Mbps.

Fine. Take the other potential sources of error out of the picture.
Plug the desktop machine directly into the ME102 access point and try
again. You might need a crossover ethernet cable.

>Anyone have any idea what could be causing this? I've tried all
>possible channel settings, and combinations of all other settings I can
>see.

--
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

Wow, thanks John & Jeff, I've obviously got a few things to try out
there.
I'll keep you posted, but thanks again in the meantime.

Regards,

Dave

"Dave Brown" <(E-Mail Removed)> wrote in
news:(E-Mail Removed) ps.com:

> Acer Travelmate laptop with built-in Intel 2200GB 802.11b/g wireless
> network adaptor, XP Pro.
> Netgear ME102 802.11b Access Point, plugged into network hub.
> 2 more desktop machines plugged into the hub, both Win 2k, it's a 100Mb
> network.
> The Access Point is approximately 3 inches away from the laptop.
>

<snip>

>
> Anyone have any idea what could be causing this? I've tried all
> possible channel settings, and combinations of all other settings I can
> see.
>

Really stupid question.....what about a wired connection on this laptop ?
What speeds do you see from that ?

(Unless there isn't a wired connection of course.)

> Really stupid question.....what about a wired connection on this laptop ?
> What speeds do you see from that ?
>
> (Unless there isn't a wired connection of course.)

No, that's a perfectly acceptable question, unfortunately the answer is
93Mbs in both directions.

Regarding the other issues that Jeff & John brought up:

>From Jeff:

> Is the ME102 running the Netgear firmware, or has someone
> installed firmware from a DWL-900AP+ or WAP11?

Original Netgear firmware. There is an update available, but it doesn't
mention anything critical as far as I can see. I'm, a bit reluctant to
change it because a) I've seen a number of postings about these AP's
being killed by upgrading firmware and b) I've had this AP for about 4
years, and it used to work find with a different laptop/PCMCIA card.
Yeah, I've just thought, I might dig out that old card and see if that
fixes things - update see end of message.

> Fine. Take the other potential sources of error out of the picture.
> Plug the desktop machine directly into the ME102 access point
> and try again. You might need a crossover ethernet cable.

No change

>From John:

> 1. Restore all settings to default values.

No change.

> 2. Don't use huge packets, which increases the cost of errors.

Using Windows networking, how can I change the packet size?

> 3. Make sure the ME102 has the latest firmware.

See answer above.

> 4. Use the latest Intel reference drivers and software for the 2200BG.

Got to try that one yet.

> 5. Move the wireless units at least a few feet apart.

No Change.

> 6. Try testing with:
> (a) Iperf <http://dast.nlanr.net/Projects/Iperf/>.

With desktop as server:
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[820] local 192.168.0.1 port 5001 connected with 192.168.0.3 port 1555
[ ID] Interval Transfer Bandwidth
[820] 0.0-10.0 sec 3.82 MBytes 3.21 Mbits/sec

With laptop as server::
------------------------------------------------------------
Client connecting to 192.168.0.3, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[884] local 192.168.0.1 port 3320 connected with 192.168.0.3 port 5001
read on server close failed: Software caused connection abort
[ ID] Interval Transfer Bandwidth
[884] 0.0-87.2 sec 48.0 KBytes 4.51 Kbits/sec

> (b) Netio <http://freshmeat.net/projects/netio/>

I ran this in server mode on the desktop, client on the laptop.
I tried it first with a wired connection, fine, I see the client both
sends and receives, giving throughput for both.
Then I tried in wireless mode. The laptop did a 1k block size
transmission, 384 kbyte/sec, then simply hung up on reception, it never
did anything else, even though the server end said it had sent.

> 7. Check the Intel statistics after transmissions

Is this to do with the reference drivers you mentioned?


Update: I found my old PCMCIA card, and it produces practically
identical figures on all tests. So that discounts the laptops built-in
network adaptor.

I've not really much idea about how wireless networks work, (I'm a
software guy, always blame the hardware), but presumably each end has a
transmitter and a receiver. I'm now guessing that the transmitter on
the AP is bad. Is that feasible?

Thanks for all your input so far, by the way,

Regards,

Dave