Improving the speed of a Wireless LAN, currently very slow

Question

I have a Netopia 3347W router, which I got several years ago. There are several laptops and two desktops in my house which connect to the internet via this router, and thus are all on the same LAN.

I've noticed recently that file transfer between PCs on the LAN is very slow. I seem to get an average of 300 kB/s, no matter what protocol I use.

In contrast, on good days I can download from the internet at 600+ kB/s (I have a 7 Megabit connection).

I connected two laptops via ethernet cable to the router and got 15-20 MB/s transferring a file over FTP, which clearly indicated the problem is the wireless.

When I ping the router, I get an average of about 4ms, which seems very high. There's no difference between the laptop being right beside the router or in another room.

The OSs on the network are a mix of XP, Vista, 7 and Ubuntu. There are no firewalls or anti virus software affecting the laptops I tested. There's no difference between the Ubuntu laptop and any other laptop, which demonstrates it's not Spyware or a virus.

I tried channels 7, 10 and 11, and it didn't make a difference. I might do further experimentation with different channels, but I really don't think it's the problem.

I turned off encryption and it didn't do anything.

Does anyone have any ideas?

Answer 1

I have a Netopia 3347W router, which I got several years ago. There are several laptops and two desktops in my house which connect to the internet via this router, and thus are all on the same LAN.

You have one of these http://www.amazon.com/Netopia-ADSL-GATEWAY-WIRELESS-3347W/dp/tech-data/B0001CJCEW/ref=de_a_smtd ? The specs for that are

Data Link Protocol: Ethernet, Fast Ethernet, IEEE 802.11b

• The maximum speed of 802.11b is 11mbit/sec (1400 kB/s).
• The maximum speed of Fast Ethernet is 100mbit/sec (12.5 MB/s)

I've noticed recently that file transfer between PCs on the LAN is very slow. I seem to get an average of 300 kB/s, no matter what protocol I use.

Wireless is a half-duplex connection shared between all the wireless clients. If you are transferring data from one wireless client to another the highest possible rate you would ever see is 700kB/s The 300kB/s you are seeing sounds about right if you have multiple wireless clients.

In contrast, on good days I can download from the internet at 600+ kB/s (I have a 7 Megabit connection).

Transferring data to the internet requires half the traffic compared to transferring data between two wireless clients.

I connected two laptops via ethernet cable to the router and got 15-20 MB/s transferring a file over FTP, which clearly indicated the problem is the wireless.

The maximum possible speed you should see is 12.5 MB/s. I'm not sure where you got 15-20 from. 20MB/s is not possible on FastEthernet.

When I ping the router, I get an average of about 4ms, which seems very high. There's no difference between the laptop being right beside the router or in another room.

a 4ms ping for 802.11b isn't bad.

Does anyone have any ideas?

Buy a new router.

Answer 2

In addition, you may consider a site survey to map the WiFi coverage at your location:

Ekahau HeatMapper is a free software tool for quick and easy coverage mapping of Wi-Fi (802.11) networks. It's the only free, easy-to-use tool that shows, on a map, the wireless network coverage in your home or small office. HeatMapper also locates all access points.

* Shows Wi-Fi coverage on a map
* Locates all access points
* Detects security settings and finds open networks
* Designed for home and small office
* Free of charge, one-minute install
* Supports 802.11n, as well as a/b/g

You may also achieve a signal improvement with a DIY parabolic dish:

Answer 3

All that I can really say is either try new aerials or try changing the channel again, Channels 7, 10 and 11 are very close together, refer to this chart:

Quite frankly, it sounds like you have pretty much tried everything I would, if changing the channel does nothing, it could simply be that the router itself has a wireless problem (check for firmware upgrades).

Lastly, it may be worth double checking if the laptop has any power saving settings that deal with battery life and signal performance.