Help with diagnosing slow wireless connection.

Factual Questions
1

Hi everyone,

Our new laptop is plagued with an annoying problem. Occasionally (and so far as I can tell, only while on our home network), the wireless connection slows down REALLY slow.

To exemplify, I have a 1.0MBit DSL connection. The other night I was downloading something and getting speeds of 4K/sec. And this was from download.com, not some rinky-dink website. I connected with my desktop, and downloaded it in seconds, but after 20 minutes, the laptop was not done. Downloads from other sites were similarly fast with the desktop and slow with the laptop over the wireless.

Here is some info, and also what I have tried:

It’s a wireless B router, D-Link 614+. I have changed the channel settings on it in an attempt to rule out radio frequency interference.

I have also implemented MAC address filtering to prevent neighbors from accidentally picking up our network. We live on a fairly large lot, so this shouldn’t be a problem, but I can see more wireless networks than mine when I scan for them, so I assume they can also see mine if they scan.

I have run Ad-Aware, SpyBot, and AVG Anti-Virus, all with updated innoculation thingies, on the laptop to see if I had any malware which was stealing bandwidth. This seems not to be the case…nothing other than tracking cookies showed up, and AVG found no viruses.

What should me next steps be? I am going to test simply plugging the laptop into the router’s lan port with a regular network cable and see what that does, but I expect that to work fine, as I think it’s just the wireless portion that’s honked. I made sure that the router’s antenna is pointed up and screwed securley into the base of the router. We have not had problems like this before, so I suspect either the equipment is dying, someone got a fancy new powerful cordless phone nearby, or something else.

Help?

2

Oh, and also, I’m sitting 15 - 20 feet away from the router, with direct Line of Sight to it, so it’s not being blocked by intervening structures.

3

Does it go faster if the laptop is plugged in to an electrical outlet as opposed to battery?

If so, your laptop probably has some power saving features that slow down the connection when not plugged in.

To fix (at least on some laptops)

Right click My Computer and choose Manage.

Click “device manager” on the left side of the Computer Management dialog

Click “Network Adapters”

Right click your wireless network connection

Choose properties

On the Advanced tab, find the “Power Management” property in the property list box

Unclick “use default value” if it’s clicked, and move slider over to the right.

Depending on your laptop, there might be an easier way to do this, but that’s what worked for me.

4

Do you have any other wireless devices that are running on the same frequency, like a cordless phone?(802.11b uses the 2.4 GHz range) Microwaves, when they’re being used, can also cause interference. Interference can cause extreme slowdowns.

5

We have a cordless phone that runs in the 900MHz range, and we’re certainly not running the micro for 20 minutes late at night.

The slowdown also appears to be unreltated to whether the unit is on AC power.

6

Also, this is a brand new laptop, Pentium M, Centrino technology and all that. I k now if I have no network activity for a significant time, it shuts down the network card, but this is just a sudden slowdown with no seeming cause.

7

Have you updated all your drivers? It might not seem lik a big thing, but maybe your windows did an auto update and now it interferes with the wireless. In addition, make sure there are no software firewalls, or if there are, that they are configured properly (though with a router, you shouldn’t need a software firewall.)

8

No software firewalls running (to my knowledge). I disabled about 3 of them as part of my de-Dell-ification when I got the laptop.

I’ll look into the driver thing, but I’d think that bad drivers would cause the card to run at sub-standard speeds all the time, instead of just intermittently, and only on my home network.

Things on ly list to check:

Make sure I have latest firmware on the Router
Change channel setting to a non-overlapping channel on the Router.

9

The next time that happens, I’d try transferring a large file from your desktop to your laptop. If it is the wireless connection, you’d expect that to be similarly slow. If not, wireless would seem not to be the problem.

Newer cordless phones or any microwave would be likely sources of temporary, intermittent interference issues.

10

Good idea. I’ll try that. My new list of to-do’s is:

Verify firmware
Change Channel settings
Transfer large file between computers.

any other suggestions?

11

I installed a wireless network for the first time last weekend. I had a similar issue: brand new Netgear router, configuration checked, no problem connecting via the ethernet cable to the PC, but the wireless connection kept slowing and dropping.

I thought I’d tried everything, but a lucky guess managed to improve it (to a reasonable, if not perfect, speed): change the channel it’s using. My Netgear router uses channel 11 by default, but changing it to channel 3 made a huge difference. My guess is that there are other access points in my building using channel 11 and the interference was disrupting the connection. It’s worth a try.

12

I actually bought a new router recently because I was certain the old one was broken. Turns out, a 2.4GHz device was causing an interference just like you’ve described. I changed the channel and the slowness disappeared.

13

Does your router have quality of service (QoS) settings? If it does, the router may be limiting the amount of bandwidth available to the wireless computer.

14

No answer here, but we had just had major headaches getting our wireless connection to work after getting the hard drive replaced. After booting up off the recovery disks, the wireless connection would work with the internal card–for about 5 minutes. Then it would drop off, even though the icon would indicate it was still connected.

We tried everything…updated drivers, re-installed the card, spent hours on the phone with our provider. They used the old “cordless phone interference” explanation over and over again, despite telling them that it worked just fine before replacing the drive. Finally, they punted by telling us that the internal card was fried.

Ah, but we had an external card, so we installed that, and it worked! And, now, as if by magic, the internal card works as well. Very strange.

15

Even if it did, this wouldn’t explain anything. While using the laptop by itself, without the other omputer, we experience random slowdowns.

Or, at least, we used to.

The other night, I downloaded new firmware, changed the channel on the router, and then, for fun, shut down the DSL modem and router for 30 seconds.

The connection is much faster now (I tested before reetting the moem and router and was getting about 275 down/315 up), about 600 down and 300 up. And so far (corossing my fingers) no sporadic slowdowns.

Thanks everyone.