To expand on the answer led-mike gave you, it really depends on the nature of the server. I suspect there's a hard limit on the number of simultaneous connections, but it's going to be REALLY big. The actual limit will depend on what your software does. Does it do some big heavy duty maths and return an answer? Not many clients. Does it just echo any packet sent to it? Lots of clients. I'm sure your application is somewhere in between, but we won't be able to give a sensible answer without know lots about your application, and skill. In the meantime, do a search on google for codeproject and io completion ports. You should see many articles that will give you more help than I ever can. Iain.
Codeproject MVP for C++, I can't believe it's for my lounge posts...