C# socket server

[Stuart Johnson]

I want to create a server app capable of accepting multiple 
thrift-clients.  As each thrift client connects, it must send a login 
struct, which will be a username and password.

I have looked at the C# classes, and I am not sure where to start.  I 
can create the socket server, but I am unsure which class I need to 
attach to my socket.