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

Web Application Stress Tool (WAST) from Microsoft is what you need.

http://www.microsoft.com/downloads/details.aspx?familyid=e2c0585a-062a-439e-a67d-75a89aa36495&displaylang=en