Wlan slower than Ethernet, sure, so what? But.. !!

[Marco_CH]

Good evening :-)

First of all Im very sorry if my thread is at the wrong place but in this forum Ive always received great answers so Ill try again :-)

Short description of my "problem":

At the moment I have 3 Computers and a 2500Mbit ADSL Line. 2 HP NX8220 Notebooks and 1 Dell Desktop Computer. All of them are connected with ethernet to my SMC7004ABR Router or cablefree using WLan.

Tonight Ive noticed something real strange. No matter with which Computer I try to download the mentioned file (or any other, i tried many) using WLan, I cannot get over 80 kb/s. When I use a direct ethernet connection on any of the computers I can download the same file at the +- same time with 350 kb/s.

Funny thing is: I can download the file with all 3 computers simultanously using WLan and all of them get the speed of about 80 kb/s. This means I download with nearly fullspeed.

But when I try again with one of the computers (no matter which) Im stuck again with +- 80 kb/s.

To me this looks as if something limits the available bandwith to each computer when using WLan.

I know that this problem didnt exist some weeks ago. I havent noticed long because I never used Wlan again. But I have an idea:

For some time I use an old compaq as network storage and downloading computer. I configured a little home network and assigned all computers static IPs, enabled portforwarding in my adsl router.

my hardware looks as follows:

netopia cayman adsl modem
-->
smc7004abr router
-->
dlink g700ap (access point, 54g)
-->
a netgear 5 port switch cause i ran out of ports
-->
cisco systems printserver connected to my router


in the netopia cayman modem i changed dhcp to 1 possible IP. this forces it to give the same WAN IP to my router everytime. this i did to get portforwarding work well and it all works fine. i doubt that here is the problem.
the router has dchp enabled to from the range .5 to .60

the lan adapters of my notebooks and the dell are given a static IP and work fine.

the wlan adapters have not been given a static IP, they run dynamic. but i tested bit and gave them a static too and it didnt have an impact on the problem.

the access point has dhcp switched off.

Im not an expert at all as you may have noticed but the network runs perfectly smooth apart from this strange problem i explained.

I hope some of you can help me out having the brilliant idea :-)

Many thanks in advance

Kind regards
Marco

[Alec]

It would definitely seem to be a wireless issue since each wireless computer can download at the 80 KB/s rate which would seem to indicate that the DSL and router are not the limiting factors. You might try also downloading a file from one of your local, wired computers and see if you still get the 80KB/s rate (adding more confirmation to the theory that the wireless connection is the culprit). I can't imagine that DHCP and dynamic addressing on the LAN side would have any impact on throughput whatsoever.

What connection rate does your wireless computer(s) report via the OS and/or their drivers? 802.11b scales down from 11mbps to 5.5mbps to 2mbps to 1mbps depending upon range and signal quality. Likewise, 802.11g scales down from 54mbps. However, there are a couple of points to keep in mind: 1) because of the collision avoidance scheme utilized by wireless technologies the real world throughput on a wireless connection is around half the rated throughput (ie, 54mbps yields ~27mbps in the real world); and 2) if you have legacy 11b devices on the same wireless network as 11g devices, I understand that it will slow all devices down to the lower 11b rates.

You may want to do a little detective work with your wireless adapter drivers and other utility software to see what channel you are utilizing and what type of signal quality you are receiving. Is it possible that a neighbor or someone else may have installed their own wireless access point? Most people just plug and go with these wireless routers, but they often are all just configured to use channel 6 by default which can lead to interference. You might try configuring your access point for channels 1 or 11 and see if that helps (even though you can select other channels, I believe that only 1, 6, and 11 are non-overlapping).

[Marco_CH]

Thanks for your help Alec :-)

I was finally able to solve the problem but still without to have a clue what the problem caused.

I used Tweak Power (beta) and re-configured my ADSL Connection. This instantly resolved my problem and I have access to my full bandwith again. Funny problem :-)

Thanks again

Marco