client server model

Well the actual network code depends on the target platform unless you are using a generic framework like SDL. Basically you just need to read a network programming guide for whatever API is appropriate for your platform. If your code is actually C++ and not C... there are a number of nice neat packages to make your life easier. I guess there are similar C APIs to help. Basically networking consists of making a connection and sending or receiving packets of data and processing them... typically some sort of buffers are involved. I wouldn't like to be more specific without more details on exactly what you are doing. If you provide some more information I'm sure someone will help you more specifically,

Dan