(this is probably more appropriate in the Network forum, but it is a tool that would be useful in Performance & Load testing)

This was recently released (open source):

from http://wanem.sourceforge.net/ :

"WANem is a WAN Emulator, meant to provide real experience of Internet, during development and test on a LAN environment. Typically application developers develop applications on a LAN while the intended purpose for the same could be the client accessing the application by WAN or even the Internet. WANem allows the application development team to setup a transparent application gateway which can be used to simulate WAN characteristics like Network delay, Packet loss, Packet corruption, Disconnections, Packet re-ordering, Jitter, etc.

WANem allows WAN network characteristic emulation and thus allowing applications to be tested in a realistic WAN environment before they are moved into production."