very high packet loss on kernel driver, fedora 10
 

Hello all,

My fedora 10 pc is suffering with very high packet loss, it's typically between 10% and 40%, also some packets have a long rtt (up to 50 seconds).
I hope someone can help me get to the bottom of it.

The device is a linksys wireless pcmcia card. I don't think this is a location/interference problem as other nearby devices are ok and I've tried moving the wireless router to beside the pc without improvement.

I've connected to other wireless routers and have the same problem.

Output of various commands follows:

ifconfig

[root@desk ~]# ping -c 1000 -q 192.168.1.254
lspci -v
Please let me know any more info is required.

Many Thanks,
ShadyCraig

Can you temporarily replace the wireless NIC in the computer?

I have tried this, however, the 2nd nic doesn't seem to support the features of the 1st as it won't attach to the wireless router. I keep getting the wpa2 passkey box, so it may not support wpa2 (I would have thought that this would be an OS feature rather than a driver or hardware ones though?).

I have also tried the 2nd nic on another wireless router without any security. This worked and gave me a consistent 0% loss. I should mention that this nic uses a different driver (ndiswrapper).

So the problem is either: a faulty nic or a faulty driver.

I will try using a live cd for my distro with the nic to see if this makes any difference.

Thanks!

I tried researching Linksys PCMCIA Wifi NICS to see what brand of chipset it might have. The brand of chipset is very important in Linux support because some brands are better supported than other. I cannot quickly determine what brand of chipset your NIC has because you did not provide the exact model name/number of this device. You should always provide this kind of detail when you are inquiring about a hardware component.

[QUOTE=ShadyCraig;3601813]I have tried this, however, the 2nd nic doesn't seem to support the features of the 1st as it won't attach to the wireless router. I keep getting the wpa2 passkey box, so it may not support wpa2 (I would have thought that this would be an OS feature rather than a driver or hardware ones though?).
Hardware drivers are often incorporated into the Linux kernel at some point. However hardware support for specific components almost always starts as an independent add-on. Sometimes driver support remains independent of the kernel because the driver developers do not license their driver under open source/GPL terms. (Nvdia, ATI, maybe others)

This makes me think that the NIC uses Broadcom chips. The following page mentions in the comments section that Broadcom chips may not work with WPA2 and may have very bad performance. However this applies to the native Linux driver. This does not apply to the Windows driver that is used by means of ndiswrapper.
http://blogs.computerworld.com/new_l...drivers_arrive

Ndiswrapper is a translation layer. It allows you to use Windows drivers for wireless NICs in Linux. Ndiswrapper is not a driver in and of itself.

Yes. If your NIC uses a Broadcom chipset then it most likely is the driver. Best solution: get a wireless NIC that uses some other chipset such as Atheros. Sorry but that's what I would do.

That is a very good idea. Good device level troubleshooting technique where in this case the device is the software.

I thought I'd provided this in the lspci output in my first post. This this is not the case can you tell me how I can find this out.

I found this ticket: http://madwifi-project.org/ticket/2148
In there someone suggested altering the rate down to 24Mbs using 'iwconfig wlan0 rate 24M'. This seems to have done the trick as loss is 0% after 500 pings now.