1. Networking Concepts

This chapter provides a (necessarily) brief intoduction to computer networking concepts. For many applications of gawk to TCP/IP networking, we hope that this is enough. For more advanced tasks, you will need deeper background, and it may be necessary to switch to lower-level programming in C or C++.

There are two real-life models for the way computers send messages to each other over a network. While the analogies are not perfect, they are close enough to convey the major concepts. These two models are the phone system (reliable byte-stream communications), and the postal system (best-effort datagrams).

1.1 Reliable Byte-streams (Phone Calls)		Sending data streams.
1.2 Best-effort Datagrams (Mailed Letters)		Sending self-contained messages.
1.3 The Internet Protocols		How these models work in the Internet.
1.4 Making TCP/IP Connections (And Some Terminology)		Making TCP/IP connections.