Most of the stuff in .NET to do with TCP/IP is in the namespace System.Net, although the useful (Socket) stuff is in System.Net.Sockets

MSDN has tons of code examples on how to use sockets sychronously or asyncronously using a callback on connects, recieves... increadibly useful stuff...

check this out...

http://msdn2.microsoft.com/en-us/lib...ts.socket.aspx