Wireless networking performance


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Royce

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Aug 25, 2003
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www.roycelithgo.com
My network comprises linksys wireless G (with speedbooster) router and all network cards also wireless G (with speedbooster). Connection strength is excellent for 2 of my PCs and good to very good for the last one. Despite all this, when I copy files from one PC to the other, copy speed averages about 1-1.5MB/s, or 8mbps - 12mbps. Even windows task manager (network tab) shows network utilisation for wireless network is 25%. Why aren't I getting anywhere near the 54mbps speed? Is 54mbps the speed for the entire network, or each adapter on the network?
 

jus to let u noe that if there is any 802.11b wireless network ard ur area...the speedbooster will b useless...n mite even cause prob...n its quite impossible to get full speed out of it...as there is interference so getting full speed of 54mpbs is quite difficult...
 

I get the same speed as you've mentioned too, even though I'm using G. Same regardless of Mac to PC or PC to PC. Don't know about Mac to Mac though.
 

you will not get the Max 54mbps unless you are running your wireless in vacuumn and your equipment are in line of sight :bsmilie:
, coz around us there are too many stray wireless signals. Furthermore, there are bound to be path fading where some signals are lost due to refraction or reflection or adsorbsion
 

alechim said:
you will not get the Max 54mbps unless you are running your wireless in vacuumn and your equipment are in line of sight :bsmilie:
, coz around us there are too many stray wireless signals. Furthermore, there are bound to be path fading where some signals are lost due to refraction or reflection or adsorbsion
Well 2 of my PCs are in the same room as the router and even then when i copy file from one PC to the other, I still only get 1.8MB/s (14mbps) copy speed.
 

Well, my laptop is less than 1 meter away from the router... :think:
 

I have been out of IT for quite a while. here is what you can try. if both terminals are USB wireless, then the problem might be the USB, you plugged into USB1.1? another way is the force the router the only use 54G and the terminals to 54G also.

the best i had sustain with G is 5MB+ there is also a 10% overhead.. which is included in the 54mbps. so when connected at 54G the fastest possible should be around 6MB.

not sure if this helps.
 

The 54Mbps is the theoretical max limit for 801.11g. It is using the 2.4 - 2.4835GHz radio frequency range. This is the so call "free" frequency range and is not owned by anyone. Most wireless equipments (including electronics equipment) use this frequency range so it can be quite crowded.

It is impossible to reach or substain transfer rate at 54Mbps as there are limited channel (11 or 13 depend on the router you use) and these are shared. By default, most older home router will use the first channel (2.412GHz). Do not know about the current generation of home routers. You can manually changed that in the router setup page.

There are other factors that could limit the transfer speed.
- drivers
- type of encryption
- number of wireless devices around your place
- single or mixed mode
- the number of devices using the same channel as you.

The transfer rate for my home varies from 24 - 54Mbps. I am able to obtain constant 24Mpbs transfer rate.

Maybe you might want to "scan" your area to check the number of wireless access points.
I am no expert in wireless networking and these are just my 2 cents worth of sharing. ;)

Please correct me if there are any mistake mention above. ;)
 

Well so far I have tried the following:
- Switching router to Single (G) mode only as all my connections are all using G.
- Ensuring all wireless cards using latest drivers and router has latest firmware.
- Change encryption from WPA TKIP to WPA AES as i believe there is a performance overheard using TKIP.

Still with all of the above transfer rate never goes much above 12Mbps. I would be very happy if I could get it above 24Mbps. I guess the only other thing to try now would be to change the channel. There are a few wireless networks in range, one of them being a Wireless B one. Could this be degrading the performance of my network? Does it matter if there are B networks in range if they are on another channel?
 

It could be multiple signals coming fomr the same network that are inerfereing with each other? I know that if i birng my laptop near my desktop one of them will lose its wireless conneciton due to the interference.
 

Ok tried shutting down my notebook, which is pretty close to one of the PCs I'm testing. Didn't make any difference to the transfer rate. :(
 

Royce said:
Well so far I have tried the following:
- Switching router to Single (G) mode only as all my connections are all using G.
- Ensuring all wireless cards using latest drivers and router has latest firmware.
- Change encryption from WPA TKIP to WPA AES as i believe there is a performance overheard using TKIP.

Still with all of the above transfer rate never goes much above 12Mbps. I would be very happy if I could get it above 24Mbps. I guess the only other thing to try now would be to change the channel. There are a few wireless networks in range, one of them being a Wireless B one. Could this be degrading the performance of my network? Does it matter if there are B networks in range if they are on another channel?
in that case disable speed booster...as 802.11b will affect it...
 

yep, i second that. if one is able to get 30+ Mbps it's considered very good liao...
Ola said:
The 54Mbps is the theoretical max limit for 801.11g. It is using the 2.4 - 2.4835GHz radio frequency range. This is the so call "free" frequency range and is not owned by anyone. Most wireless equipments (including electronics equipment) use this frequency range so it can be quite crowded.

It is impossible to reach or substain transfer rate at 54Mbps as there are limited channel (11 or 13 depend on the router you use) and these are shared. By default, most older home router will use the first channel (2.412GHz). Do not know about the current generation of home routers. You can manually changed that in the router setup page.

There are other factors that could limit the transfer speed.
- drivers
- type of encryption
- number of wireless devices around your place
- single or mixed mode
- the number of devices using the same channel as you.

The transfer rate for my home varies from 24 - 54Mbps. I am able to obtain constant 24Mpbs transfer rate.

Maybe you might want to "scan" your area to check the number of wireless access points.
I am no expert in wireless networking and these are just my 2 cents worth of sharing. ;)

Please correct me if there are any mistake mention above. ;)
 

If network speed is the issue, there's always gigabit lan :thumbsup: :sticktong
 

Klose said:
If network speed is the issue, there's always gigabit lan :thumbsup: :sticktong
I think you will find most people use wireless cos wired network not practical (unless happy to live with long cables running all over the house). Of course if wired network were practical in my home then i would be using it.
 

Copying files over windows is not a good measure of network speed. The overheads are incredibly high, and the actual 'payload' - the files copied - are only a small part of the real traffice happening. You can verify this by copying one 1GB file, and then copying 10000 100kb files. Though they are the same size (1GB), the small files will take many times longer.

For the wireless issue, you can do a simple test: copy the same files using a LAN wire - same PCs, same router. My guess is that you would get 2-4 mbytes/s (theoretical 12.5 mbytes/s max). If so, the bottleneck is the OS, and whatever you 'fix' with the wireless system is not going to help.

You can improve file copying speed by using larger packets sizes, but only if your hardware (adapters and router) supports it. The improvement is mostly with large files only.
 

ST1100 said:
Copying files over windows is not a good measure of network speed. The overheads are incredibly high, and the actual 'payload' - the files copied - are only a small part of the real traffice happening. You can verify this by copying one 1GB file, and then copying 10000 100kb files. Though they are the same size (1GB), the small files will take many times longer.

For the wireless issue, you can do a simple test: copy the same files using a LAN wire - same PCs, same router. My guess is that you would get 2-4 mbytes/s (theoretical 12.5 mbytes/s max). If so, the bottleneck is the OS, and whatever you 'fix' with the wireless system is not going to help.

You can improve file copying speed by using larger packets sizes, but only if your hardware (adapters and router) supports it. The improvement is mostly with large files only.
How then to benchmark the wireless performance from one PC to another if not copying files? Is there some software that can be used to do this? Would another transfer method have less overhead, eg. ftp?

I don't think I'm able to increase the packet size for my router.
 

What is the model number of your linksys router & network cards?
 

Royce said:
The router is WRT54GS. Network cards are WMP54GS.

are you using the stock firmware or the third party ones? i suggest u ditch the stock firmware and use Tailsman (Must Pay) (or FreeMan WRT54GS v1.0.4 btw what version is your router?
 

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