Wireless 802.11g LAN performance problem

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sunbird

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I have a very simple wireless home LAN:
2 x XP SP2 PCs with 802.11g PCI adaptors (Mecer WPG2400) set to AUTO detect speed, connections ("good" to "excellent")
1 x 802.11g AP (Mecer ARM904) connected via ethernet (cable) to ADSL (192kbs) router and WAN.
LAN is connected (at 54Mbps) and working, upload & download from ISP is fine, so this is not my problem.

My problem is slow throughput transferring file from PC to PC on the wireless LAN (+- 5Mbps) - my understanding is that I should be able to obtain 20-30Mbps, depending on conditions.

In order to eliminate the quality of the wireless connections as the possible bottleneck, I connected a 3rd computer via an ethernet CABLE to the AP to test each wireless connection separately. Both computers upload at a consistent 21-22Mbps to the test PC, as expected, but both computers download from the test machine at around 5Mbps and judging from the
netmeter graph, it also looks as though the connection speed jumps widely during the transfer. I had expected both TX and RX rates to be the same, but this is not the case.

I am using QCheck to measure throughput and CableNut to tweak - so far without success.

Any assistance from you gurus out there would be greatly appreciated :confused: :confused: :confused:
 
Thanks for responding! I have the latest Abocom drivers for both the PCI adaptors and the AP. The firewall and encryption are disabled.

BTW, have you used the WPG2400 and ARM904 in a similar setup? If so, have you tested the download throughput?
 
Transferring large files between computers that connect wirelessly to an AP can be extremely frustrating, as it is very slow. For me wi-fi is only good for browsing the web, for LARGE file transfer I hardwire it. You are correct when you say should expect a ~25Mbps transfer rate, which is the BEST case scenario with the computers and AP a couple of meters from each other with nothing but air inbetween them. With regular Cat5 cable you have 2 wires for TX and 2 wires for RX, with wi-fi you have ONE radio that has to do both RX and TX.

Are both your PC's identical? I've noticed transfer differences between my laptop and 2 desktops where one PC is differently configured than the other one.

I guess this doesn't really answer your question, sorry.
 
The problem is the Mecer wireless stuff manufactured by Abocom.
It is far inferior to other products on the market. Get yourself some decent kit and your problems will be solved. Mecer AP's always seem to disconnect
for no apparent reason.
 
so wifi i only good for general browsing & small files?
 
Eh. No.

I just said that it would never match Ethernet speeds. It will work for large files too, but it's like copying a file to a 2-speed CDR/W versus a 20-speed CDR/W. All it means is that large files will take longer. It doesn't mean it won't work.

Ask yourself this: Is ADSL only good for browsing & small files? No. You can do large files on it too. Wifi can do 10-40 times as fast as DSL can. Does this mean it's only good for browsing & small files? No.
 
Try enabling the turbo 4x mode

check if your firmware on the AP is prior to 904_1618
 
You sure youre not getting bits (b) and bytes (B) confused ?

also, if youre transferring via the AP, expect half speed as it has to send out the same traffic youre sending it at the same time, so the traffic is essentially doubled. To test stick one pc in host ( or infrastructure ) mode and transfer from pc to pc. You should go considerably faster. Think of an AP as a hub, cause anything you send it, will echo back to you as the AP retransmits the data for the other pc.
 
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