In Linux, you deal with the network stack via sockets. I assume you are familiar how they work and you have got some basic network programming knowledge in C. What I mean is that you know what functions like socket(), bind(), listen() do, how you should call them and how to implement a simple client-server application. For the purposes of this and the following posts I have created a project in GitHub. You will find there all the code mentioned here. Please check the one-to-one_basic branch now and make sure you understand the code there. It is nothing fancy - client and server application exchanging few messages over SCTP. Anyway if you need a refreshment or you are new to Linux socket programing check some other tutorial on this topic. There are a lot of good ones out there so just pick one you like. My personal best is Beej's Guide to Network Programming.
Disclaimer about the code
Please note that the code is not at all intended to be used on production systems. It is created as a demonstration for the interfaces that I shall write about. It has got some basic checks, but it is far from production ready. If you plan to use it in your project please take some time and add proper error handling. You have been warned.