Netbook (Samsung N220) on Ubuntu 10.04 slows down WiFi for other computers

Question

I encountered a really odd problem with my new netbook.

I am running Ubuntu 10.04 on a Samsung N220 Mito. So far everything worked fine.

Now I tried the machine for the first time in our work group where we have a wifi (with internet access) for all laptops. The wifi is controlled by a computer running Suse 9.3 which provides a DHCP server and imposes a firewall.

At the moment there is only a macbook in the wifi, where no problems with the internet or wifi connection are encountered.

Now coming to my actual problem: In addition to the macbook i connect the Samsung N220 to the Wifi.

1. Problem: My download speed is for some reason limited to 70KB/s max. This is neither a limitation of the server/website i browse on, nor a configuration of the netbook: at home i have > 500KB/s download speeds. Furthermore, it is not a default limitation for "untrusted" or "new machines" in the wifi, as for instance other new laptops get full speed internet with our wifi.

2. Problem: Once the Samsung N220 is generating traffic in the wifi, the wifi is slowed down dramatically for all other machines: I run a ping to the router from the macbook. The ping times with the N220 ideling are 2-6ms. When I start downloading or browsing in the web with the N220 the ping speed drops to > 800ms. Vice versa, when the macbook is generating the traffic the ping of the N220 to the rooter stays constant at around 2-6ms. So clearly, it is some problem originating from my netbook or maybe its treatment in the wifi.

Thanks for any help

Answer 1

1. Generally the wifi connection will be shared by all clients. Hence it is just normal that the speed of the network connection may drop.
2. Most access points support multiple WLAN standards (a/b/g/n) today. If there is a client which does not support the latest and fastest WLAN standard the accesspoint may fallback to an older and slower standard to establish a connection with this client. This fallback to the older standard can be applied to all clients in the network, leading to slower connections.

Anyway it does not sound like point 1 oder 2 is the problem you are facing.

Maybe it would be helpful to get more details.

• What channels and frequencies the access point is using.
• What other networks are around?
• What drivers are used?
• Did you face the problem at other wifis, too?

Maybe you are not using the most current driver availible.

http://forum.ubuntuusers.de/topic/vor-dem-erstellen-eines-neuen-beitrags-bitte-/

The link leads to a GERMAN forum entry, explaining how to collection important information about the network configuration with ubuntu. Even if you don't understand German you can use the commands to provide more details.

Answer 2

I have a problem using 10.10 on my Samsung n130 whereby the wireless locks up and I have to reboot the computer to fix it.

I cured the problem by using the NDIS drivers instead of the built-in Linux ones.

This may also solve your problem as well. Install the Windows Drivers package and use that to install the NDIS drivers from Samsung (NDIS drivers are the Windows XP drivers) and see if that solves your problem.