bandwidth and traffic simulator for web apps?

Question

Can you suggest how to create a test environment to simulate various types of bandwidths and traffic in a web app?

Or maybe an open source program which does this against

Answer 1

The closest I can think of is doing something similar with VEDekstop from Shunra..

Simulating High Latency and Low Bandwidth in Testing of Database Applications

Shunra VE Desktop Standard is a Windows-based client software solution that simulates a wide area network link so that you can test applications under a variety of current and potential network conditions – directly from your desktop.