Computer Networks: A Systems Approach, designed for college-level course in advanced network design and operation, providing network applications programmer with detailed information about how networks do their thing. While Computer Networks is not a user manual or technical reference, it provides in-depth background on how network architectures and protocols work. In the beginning, Larry Peterson and Bruce Davie discuss why networks are important and talk about where networks may be going in the long term. There's the interesting part - complete with plenty of C code - in which the author actually develop a network protocol called A Simple Protocol (ASP).