Bandwidth problems...

[negativeB]

Hello everyone...

I've got a rather troublesome problem. I have all three computers in
my house networked through a D-Link DIR-625 wireless router. One is
hardwired to the router itself and presents no problems for me. The
other two are on a secure wireless network that I set up myself.
However, the two wireless computers almost always have a low or very
low connection and never reach download speeds over 16 KB/sec.

When I first set up the network I let D-Link run it, and ran into
problems with it just dropping the connection all together. So I set
it up so that XP controls all network activity, which assuaged the my
connectivity problems, but created others in its place. The two
computers are only about 50 feet from the router, and I figured with
the router being a RangeBooster, 50 feet is no big deal. But the
wireless computers still connect at low or very low, and now they
never reach speeds in excess of 16 KB/sec.

The computer that is hardwired into the router operates as it should.
We have no speed problems associated with it. Which leads me to
assume that the problem lies not in the hardware, but in the wireless
portion of the network, and how XP controls it. All three systems are
running XP SP2, and work individually when I hardwire them into the
router, but when I take them wireless the speed drops drastically.

Any thoughts?...

 

[Chuck [MVP]]

Hello everyone...

I've got a rather troublesome problem. I have all three computers in
my house networked through a D-Link DIR-625 wireless router. One is
hardwired to the router itself and presents no problems for me. The
other two are on a secure wireless network that I set up myself.
However, the two wireless computers almost always have a low or very
low connection and never reach download speeds over 16 KB/sec.

When I first set up the network I let D-Link run it, and ran into
problems with it just dropping the connection all together. So I set
it up so that XP controls all network activity, which assuaged the my
connectivity problems, but created others in its place. The two
computers are only about 50 feet from the router, and I figured with
the router being a RangeBooster, 50 feet is no big deal. But the
wireless computers still connect at low or very low, and now they
never reach speeds in excess of 16 KB/sec.

The computer that is hardwired into the router operates as it should.
We have no speed problems associated with it. Which leads me to
assume that the problem lies not in the hardware, but in the wireless
portion of the network, and how XP controls it. All three systems are
running XP SP2, and work individually when I hardwire them into the
router, but when I take them wireless the speed drops drastically.

Any thoughts?...

Low WiFi speed can come from a number of problems. A common problem is low
signal level, another is shared use of the WiFi spectrum.
<http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html>
http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html

I would start with a WiFi environment survey. Know what the signal strength is,
and know what your neighbours may be doing.
<http://nitecruzr.blogspot.com/2006/06/analyse-your-wifi-environment.html>
http://nitecruzr.blogspot.com/2006/06/analyse-your-wifi-environment.html

--
Cheers,
Chuck, MS-MVP 2005-2007 [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.

 

[Lem]

Hello everyone...

I've got a rather troublesome problem. I have all three computers in
my house networked through a D-Link DIR-625 wireless router. One is
hardwired to the router itself and presents no problems for me. The
other two are on a secure wireless network that I set up myself.
However, the two wireless computers almost always have a low or very
low connection and never reach download speeds over 16 KB/sec.

When I first set up the network I let D-Link run it, and ran into
problems with it just dropping the connection all together. So I set
it up so that XP controls all network activity, which assuaged the my
connectivity problems, but created others in its place. The two
computers are only about 50 feet from the router, and I figured with
the router being a RangeBooster, 50 feet is no big deal. But the
wireless computers still connect at low or very low, and now they
never reach speeds in excess of 16 KB/sec.

The computer that is hardwired into the router operates as it should.
We have no speed problems associated with it. Which leads me to
assume that the problem lies not in the hardware, but in the wireless
portion of the network, and how XP controls it. All three systems are
running XP SP2, and work individually when I hardwire them into the
router, but when I take them wireless the speed drops drastically.

Any thoughts?...

The DIR-625 is a "draft-n" device. It will *only* deliver even *some*
of its advertised range and speed improvements if used with another
"draft-n" device, preferably one from D-Link. So ... what are you using
for wireless adapters in your two wireless computers?

Even so, the DIR-625 should be backwards compatible with 802.11G
adapters, which have a theoretical max data rate of 54 Mbps.

Note the word *theoretical.* Regardless of what your wireless
configuration software (including Windows) tells you, you are not going
to be connecting at anywhere near this data rate. See this wikipedia
article for some ideas: http://en.wikipedia.org/wiki/IEEE_802.11

Moreover, your "50 feet" is not necessarily the same as my "50 feet."
Fifty feet in a straight line in the open air inside a Faraday cage that
blocks all external electromagnetic radiation is one thing. Fifty feet
through a number of walls and floors (especially if they have metal
studs, beams, or mesh, or foil-backed insulation) in a "noisy"
radio-frequency environment is another story entirely.

See http://www.ezlan.net/latency.html and
http://www.cites.uiuc.edu/wireless/speed.html for some discussion of the
above.

Test your setup by bringing the wireless computers physically close to
the router. Move the router away from any CRT monitors or speakers. If
there are nearby sources of 2.4 MHz interference (baby monitors,
cordless telephones, microwave ovens) make sure that they are not turned
on. Now test your wireless LAN by transferring a large (~750 MB) file
between the wired computer and one of the wireless ones and measure the
time it takes. Remember that the datarate specs are given in Megabits
per second (not megabytes).

For comparison, take a look at the "wireless" section of the tests
reported here:
http://www.bit-tech.net/hardware/2007/03/05/wireless_router_group_test/1

TrendNet TEW-631BRP (pre-n) 750 Megabytes in 202 sec 29.7 Mbits/s
Zyxel P-336M (G) 750 MB in 320 sec 18.8 Mbits/s
Netgear DG834N (pre-n) 750 MB in 347 sec 17.3 Mbits/s
D-Link DSL-2740b (pre-n) 750 MB in 196 sec 30.6 Mbits/s

The test claimed that the Netgear reverted to G because of a firmware
upgrade. Note that the G speeds were close to what the wiki article
says is "typical" G data rate, the 2 n speeds were less than half.

Assuming that what you are getting is 16 Kbits/sec (not 16Kbytes/sec),
that's not too bad.

--
Lem -- MS-MVP - Networking

To the moon and back with 2K words of RAM and 36K words of ROM.
http://en.wikipedia.org/wiki/Apollo_Guidance_Computer
http://history.nasa.gov/afj/compessay.htm

 

[Jack \(MVP-Networking\).]

Hi
When transferring files Windows usually measure the "Speed" in KB (B=Byte).
16Kb/sec. is about 1500Kb/sec. (b=bit). This "Speed" is low even for
802.11b.
Wireless is extremely depending on the environment, some environmental
problem can be identified by experienced users, but in many cases special
instrumentation is needed to identify the environmental effect on the
Wireless signal.
As a first step put one of the Wireless computers 3 feet away form the
Wireless Router and check the outcome, if it is too low as compare to the
numbers mentioned by Lem you need to work on your hardware.
If it is reasonably OK, then you have a distance problem. Common mistake
done by user is to try to solve distance issue with one more powerful (or at
least claim to be more powerful Wireless Device)
This approach does not work most of the time because whatever "kills" the
signal with one Router usually "kills" it with so call better Router
(Typical Wireless Router has a transmitting power of 30mW)
The Best solution for Wireless Difficulties is to extend the coverage by
using extra Wireless sources in the environment to compensate for
obstructions and dead spots.
Given that decent Wireless Router can be found bellow $50 it does take much
to use one or two extra Wireless Routers/Access Points to cover well most
difficult End-User environments.
The following describe common method to extend Wireless coverage.
Extending Distance - http://www.ezlan.net/Distance.html
Wireless Router as an AP - http://www.ezlan.net/router_AP.html
Wireless Modes - http://www.ezlan.net/Wireless_Modes.html
Wireless Bridging - http://www.ezlan.net/bridging.html
Hi Gain Antenna - http://www.ezlan.net/antennae.html
Jack (MVP-Networking).

 

[Lem]

The DIR-625 is a "draft-n" device. It will *only* deliver even *some*
of its advertised range and speed improvements if used with another
"draft-n" device, preferably one from D-Link. So ... what are you using
for wireless adapters in your two wireless computers?

Even so, the DIR-625 should be backwards compatible with 802.11G
adapters, which have a theoretical max data rate of 54 Mbps.

Note the word *theoretical.* Regardless of what your wireless
configuration software (including Windows) tells you, you are not going
to be connecting at anywhere near this data rate. See this wikipedia
article for some ideas: http://en.wikipedia.org/wiki/IEEE_802.11

Moreover, your "50 feet" is not necessarily the same as my "50 feet."
Fifty feet in a straight line in the open air inside a Faraday cage that
blocks all external electromagnetic radiation is one thing. Fifty feet
through a number of walls and floors (especially if they have metal
studs, beams, or mesh, or foil-backed insulation) in a "noisy"
radio-frequency environment is another story entirely.

See http://www.ezlan.net/latency.html and
http://www.cites.uiuc.edu/wireless/speed.html for some discussion of the
above.

Test your setup by bringing the wireless computers physically close to
the router. Move the router away from any CRT monitors or speakers. If
there are nearby sources of 2.4 MHz interference (baby monitors,
cordless telephones, microwave ovens) make sure that they are not turned
on. Now test your wireless LAN by transferring a large (~750 MB) file
between the wired computer and one of the wireless ones and measure the
time it takes. Remember that the datarate specs are given in Megabits
per second (not megabytes).

For comparison, take a look at the "wireless" section of the tests
reported here:
http://www.bit-tech.net/hardware/2007/03/05/wireless_router_group_test/1

TrendNet TEW-631BRP (pre-n) 750 Megabytes in 202 sec 29.7 Mbits/s
Zyxel P-336M (G) 750 MB in 320 sec 18.8 Mbits/s
Netgear DG834N (pre-n) 750 MB in 347 sec 17.3 Mbits/s
D-Link DSL-2740b (pre-n) 750 MB in 196 sec 30.6 Mbits/s

The test claimed that the Netgear reverted to G because of a firmware
upgrade. Note that the G speeds were close to what the wiki article
says is "typical" G data rate, the 2 n speeds were less than half.

Assuming that what you are getting is 16 Kbits/sec (not 16Kbytes/sec),
that's not too bad.

Oops. strike that last sentence

--
Lem -- MS-MVP - Networking

To the moon and back with 2K words of RAM and 36K words of ROM.
http://en.wikipedia.org/wiki/Apollo_Guidance_Computer
http://history.nasa.gov/afj/compessay.htm