how to do Net Limiter?

Question

Hi
I am developing a windows application in c#. I have two types of web request 1. critical 2. non critical request. i have 300kbps net connection and average download speed of 40kbps. i need to split the available bandwidth into 3 part. one for other application and the rest to two types of request. In short, i need to use a part of the bandwidth to my application. In that each request uses its own limit.. can anyone please help me to do this. thanks in advance..