wlan failing HP 8740w

[Guest]

Dear all,

I recently switched over from Windows to Kubuntu. After 15 years of administering corporate Windows networks I decided to move over to the wild side on my laptop. However I ran into trouble;

I have an HP 8740W and I made a fresh install of Ubuntu 12.04 lt on a new harddrive. Everything works fine, except that the wlan loses connectivity the very moment I start a bigger download using firefox or any other browser. For example anything from the Microsoft Licensing website, .iso files sizing from a few hundred mb to a few gb fails to download and makes the wlan unavailable.

Normal webbrowsing using firefox works fine. The same wlan, on the same physical spot, using other devices as iPad, other laptops, imac or smartphones it works fine. The problem only occurs on this HP with Kubuntu. I tried four different access points (hp msm, zte 3g mobile hotspot, zyxel p-660hw and even internet sharing from a windows phone).

Eventually the wlan connection comes back after a few minutes.

It cannot be hardware related, as the same hardware using Windows7 works flawless.

Altering MTU, as suggested somewhere, did not make any difference. I tried various different values all without change in behaviour.

Any ideas what might be the cause of this behaviour ?

[Snowhog]

Do you experience the same problem if you connect wired? By the way, welcome to KFN!

[GreyGeek]

According to this HP website there are three wifi devices associated with that PC.

What does

lspci | grep Network

show?

Once we know the wireless firmware in your PC we can use the modinfo command to see if the kernel module for it has any settable parameters which might help. If not, then the problem may lie with the NetworkManager application. I had an identical problem with the Atheros 9462 chip in this brand new Acer V3-771G laptop. I plugged in an ethernet cable from from the back of my wireless modem and then installed six wicd applications ignoring two; the i386 version and the wicd-gtk+, which is for Gnome, and then I removed plasma-widget-networkmanagement and network-manager-pptp and network-manager, and their dependencies, which are usually automatically selected. I also installed the wicd-kde client for wicd. Then I ran the client, configured my essid, type and password and then restarted (I recommend just rebooting until you learn how to use the command line to start, stop and restar services) the network.

With wicd my wireless connection has been very strong and rock solid. I've found that when I have my wireless set for automatic mixed mode, the connection often switches between various rates, depending on the distance from the wireless router. Close to it the G band seems to predominate, but the farther I move from the wireless router the more often the 120 to 130Mb/s bandwidth is selected.

[Guest]

Thanks for a fast answer.
lspci | grep Network tells me that I am equipped with a Intel Centrino Ultimate-N 6300 (rev 35).

Wired connection works fine.

As suggested by GreyGeek, I removed the plasma-widget-networkmanagement, network-manager-pptp and network-manager and installed wicd applications. For now it seems to have done the trick. I was able to download a bunch of files.

Thanks a lot!