Wireless connections dropping

[jjtbt]

I have one 3com 8250 wireless access point configured with WPA-PSK authentication and TKIP encryption and set to use 802.11g only. 25 PC's (7 windows 98, 7 windows 2000, 11 windows xp sp2) and 6 HP LaserJet 1320nw printers are connected wirelessly to this AP. Each PC has a 3com 11a/b/g wireless PCI adapter installed and I'm using the 3com wireless lan manager software to configure the card.

Intermittantly (maybe 2 times a day) all of the windows 2000 and XP PC's lose their connection or association with the access point and throw up a "read file failed" error box on the screen. Clicking "ok" on the error message just causes it to go away for a second and then it reappears again. Sometimes the PC's get the connection back, but sometimes not and the only choice is to reboot. Sometimes the printers need to be turned on and then off again when this happens to get them to associate again.

Since implementing WPA-PSK authentication and TKIP encryption the PC's are also fairly slow to associate to the AP. The PC's are all using static IP's and I have set the AP and all the PC's to use channel 2.

Does anyone have any suggestions as to why these PC's are dropping their connections in this way?

 

[GlenJohnson]

Couple thoughts. How long has this been going on? Why are you not using the default channels, 1, 6 or 11? Why not use dhcp on the pc's? Have you noticed a certain time this is happening or is it anytime during the day? Good luck.

Glen A. Johnson
Johnson Computer Consulting
If you're from Northern Il, Southern Wi, feel free to join Tek-Tips in Chicago IL

 

[jjtbt]

It started after I made a ton of changes: I made a couple changes to the AP...one was to define the channel on the AP & clients (I thought this might help speed up the time it takes the clients to associate) and the other was to implement the WPA-PSK auth & TKIP encryption. I also have been installing some new XP Pro sp2 PC's and have added the LaserJet 1320nw printers. And I upgraded the AP to the most recent firmware and the software for the wireless network cards were also updated.

It started happening after all this occurred so I'm not sure exactly which change might be the cause. It doesn't seem to have any bearing on the time of day so far.

I used channel 2 because I found this on the 3com knowledgebase about the 8250 AP:

"Radio performance is optimized when selecting channel 2-10
Channels 1 and 11 have slightly reduced maximum power output for regulatory compliance reasons. Channels, 2, 6, and 10 are recommended for collocated radios. When multiple access points are deployed in the same area, be sure to choose channels separated by four channels to avoid channel interference. You can deploy up to three access points in the same area; for example, Ch2, Ch6, and Ch10."

(I will eventually be adding 2 more access points.)

I will be installing a new Windows 2003 server next month and at that time I am planning to implement DHCP, but right now all IP's are all statically defined.

I posted this on a different forum also and they pointed to the channel selection as well. So I will change the channel tomorrow morning and monitor the signal strength on the clients to see if is an interferance issue.

I'm open to any other suggestions...thanks!

 

[GlenJohnson]

Use channel six, and try using a hosts file between a couple and see if it helps them stay together. Good luck.

Glen A. Johnson
Johnson Computer Consulting
If you're from Northern Il, Southern Wi, feel free to join Tek-Tips in Chicago IL