Wifi drops large files

[newera]

Hi,
I have setup up a WIFI network and after a lot of tests and new hardware I managed to get a stable signal. Actually using Atheros utility I always get an Excellent signal and I transfer at 108mps.

I have a D-LINK 624 together with a directional antenna and a PCI D-LINK on another PC.

I have problem when coming to transfer large files. Actually I have a file of 1.8GB and when I try to transfer it after about 30 seconds the router stops working and the an error network is not available comes up.

I do not have any problem when coming to stream video or use MP3.

Thanks

[M/Q]

The key bit of evidence is that it only happens to file transfers. That is TCP traffic where as streaming video is UDP or connectionless. TCP uses error checking and will retransmit the packets until it gets it right.

The trick is to find what is causing the errors. What kind of signal strength are you getting? Are there any other wireless networks in the vicinity? Do you have any other wireless devices in the facility?

[newera]

Hi,

I managed to copy the file. I used the PC that has the PC wifi card and started the transfer from it instead from the PC that has a direct conection to the router even though I do not know whether this makes a difference. (Transfer took 11 minutes)

Actually signal strength is excellent using Atheros utility. However Windows shows it as Good/Very Good.

I realized that when the data was being transferred signal was moving between Excellent and Good using Atheros Utility. It seemed that when Atheros was switching to 108mps the signal went down to Good.

I have some wireless devices but I do not know if there interfere.
MCE keyboard
Wireless remote control.

I also have a mirowave in the vicinity but it was not switched on.

Thanks

[M/Q]

What about other wireless networks?

[newera]

Hi,
Yes there is another wireless network but the signal for this network is low. It also seems that it is transmitting on the same channel (on channel 6). However I cannot change the channel number from my router because it is disabled.

Thanks

[M/Q]

That is too bad as that very well could be the problem. You may want to read my sticky at the beginning of this part of the forum about "Confronting WZC". As that might explain what could be happening.

Why is it you can not change the channel, I do not quite understand that.

Further more there are also a few things to tweak your wireless router to get the best out of the signal without loosing connection.

First of all try updating to the latest firmware. The vendor may have tweaked or fixed a problem with the wireless signal and therefore a new firmware may help.

Position the Router in the highest place possible. dont put it in the basement this will affect wireless signal strength.

If your wireless devices are all 54G then if possible set your router to G only. if not set Wireless to B only (unless you have B and G devices) though B mode will give better signal than G

Adjusting the "RTS Threshold" can help alleviate Packet loss. If one of the Wireless computers can obtain an IP address but can not ping, then set the "RTS Threshold" to 2304

Adjusting the "Beacon Interval" can help association problems. If there is a wireless adapter that is able to see the access point, but is unable to get locked, try adjusting the "Beacon Interval" to 50 Also, forgot to mention I hope you do not have Broadcast SSID disabled as that is not helping security and it hurts the overall connection.

Adjusting the "Fragmentation Threshold" can help association problems. If there is a wireless adapter that is able to see the access point, but is unable to get locked, try adjusting the "Fragmentation Threshold" to 2304

The last thing I wanted to mention is that the signal strength variance is suspect. That could be from trying to lock onto that other wireless source, interference or poor conditions between the router and client.

[newera]

Hi,
Thanks for the long reply. When I open the configuration manager for my router the channel number is disabled and therefore I cannot change the channel number from where the router is transmitting because dynamic turbo is enabled on the router and this only transmits on channel 6.

Thanks, i will try all the settings you told me.

I do not think the signal is the issue. I bought a directional antenna (D-LINK) and therefore it is quite strong.

Once again thanks

[M/Q]

I would suggest getting off of the turbo then and running some tests. If the wireless client application can sense it then it is having an affect.

[Mock]

I got alot off information that descripes this problem, my config is

D-Link DWL-4300 Gameing Launge Router Firmware V1.6Eu
Linksys WRT-55AG Router
D-link G650 Xtreme Wireless PCMCIA Cardbus
LevelOne PCMCIA 108Mbit 0300

-----
Laptop = D-Link G650
Workstation = 10/100/1000 Linkspeed 1000Mbit
D-Link DWL-4300 Router
Cabel Modem 10/100 kabel

The Levelone and Linksys router is just for test basis and is not i use

my expirence with this problem is the same when copy of large files it takes about 10-15 sec before losing connection. I ran some test how to maximize og minimize the problem

Info
I can reach 3500-4300 Kbps with super G and 2000-2300 Kbpswhen this problem appears

I tried
RTC from 10-65000 = same problem
MTU Router 500/1500/3000 = same problem
Disable Cabel modem = same problem
Mixed mode / Only G = same problem
Static IP laptop = same problem
Windows wireless manager on/off = same problem
Channel Change 3 & 6 after test with net stumbler = same problem
Delete all old LAN/Wireless connection with Regedit = same problem
Removed router away from metal and kabels. = same problem
Distance 2 meters with perfect signal = same problem
Disconnect all kabels from router exept workstation = same problem
Speed on workstation 10/100/1000 mbit = same problem
No error in router Log
disabled all programs in task manager = same problem

Disabled super G = makes the file copy better and it takes longer before it disconnect i manage to copy 4 GB with super G disabled but when running
bittorrent it still disconnect after 1-5 minute

Disabled all Turbo = turbo on super G
Tried diffrent super G setting = same problem
Tried to lower the speed on Wifi = still not better than 54mbit
Disabled Harddisk cache = Same Problem and same speed
Disabled all powersaving on Netadaptor and router = same problem
change signal strengh = same speed and still disconnects same place
removed all securty on router = same problem

Before i had the linksys router and Levelone Pcmcia running with 54mbit pretty stable, but this was not super G. i could still get disconnected but never when copying files. why i change router was because i first had alot of trouble with my cabel company and the DHCP server everytime my linksys router got a wrong IP and could´t connect to the internet. after i change to d-link that problem disapeared

my new project will be getting af Workstation up running PCI-Wifi to verify if it could be a problem with the laptops cardbus port or some windows problems

[Mock]

One of the importen things that maybe could be a problem with large files drops. is that my windows still runs Windows XP Pro Sp1 because i run som Remote software that not works with SP2. i looked i some of the other treads but couldt confirm for sure if microsoft had problems with Wifi in SP1

[Mock]

Ihhhh ahhh dooo. After i upgraded my XP SP1 to SP2 i still dont worked. but now after worked with this problem for about 10 hours. i tried one of the last things, downgrade my router to an older firmware V1.6w to 1.4 after that i could copy a 4 Gb file with about 4.3 MB/s. im so happy right now to see some progress. now ill try to send alot of packet at the router too see if it still can hold its connection