I’ve had a lot of problems with the Intel wireless cards, when connecting to Wireless N Routers.
The speed cuts off, or drops to 1MB/s, you can set the rate manually by issuing the following command, replace wlan0 with the equivalent for your system, but usually it’s wlan0 unless you have multiple wireless cards.
iwconfig wlan0 rate 54M
This is a temporary solution and it won’t solve the problem permanently.
To solve this permanently issue the following command, to create a new file:
echo "options iwlagn 11n_disable=1" > /etc/modprobe.d/intel_11n_disable.conf
After this we need issue the following commands:
Then we need to either restart the system, or we can just issue the following commands to reinitialize the wifi driver.
modprobe -r iwlagn modprobe iwlagn