I have installed xcode 4.3.1 on my machine running Lion.
I can\'t find the Network Link Conditioner tool anywhere.
I have checked the utilities folder, also
Update on the answer December 2019 Xcode 11.1.2
Apple has moved Network Link Conditioner Tool to additional tools for Xcode
Go to the below link
https://developer.apple.com/download/more/?q=Additional%20Tools
Install the dmg file, select hardware from installer
select Network Link conditioner prefpane