.net collection for fast insert/delete

Question

I need to maintain a roster of connected clients that are very shortlived and frequently go up and down. Due to the potential number of clients I need a collection that supports

Answer 1

How do you need to find the clients? Is a Tuple/Dictionary necessary? You're more than likely to find something that solves your problem in the Jeffrey Richter's Power Collections library which has lists, trees, most data structures you can think of.