Limit my upload speed at OS level ? I know my upload speed is limited at about 100/110KB/s, sometimes I reach this limit and it impacts the connexion of other computer of my home network. 

Is there a way to tell OSX to limit its upload speed to (for example) 80KB/s ?
Network Link Conditioner

You can create a custom profile for Network Link Conditioner, using the following settings:




It is a free download in Xcode (go to Xcode → Open Developer Tool → More Developer Tools… and download the Hardware IO Tools for Xcode).