Limit Internet Bandwidth Usage (internet speed) in Ubuntu

#> sudo apt-get install wondershaper

#> sudo wondershaper eth0 1024 256

this will limit the download speed to 1024 Kbps and upload to 256 Kbps. Remember that this limit is for all internet traffic i.e torrent, ftp, browsing and any thing else.

If you want to remove these limits use

#> sudo wondershaper clear eth0

again replacing eth0 with your interface name