Network design

3
Network Design
Before purchasing equipment or deciding on a hardware platform, you should have a clear idea of the nature of your communications problem. Most likely, you are reading this book because you need to connect computer networks together in order to share resources and ultimately reach the larger global Internet. The network design you choose to implement should fit the communications problem you are trying to solve. Do you need to connect a remote site to an Internet connection in the center of your campus? Will your network likely grow to include several remote sites? Will most of your network components be installed in fixed locations, or will your network expand to include hundreds of roaming laptops and other devices? In this chapter, we will begin with a review of the networking concepts that define TCP/IP, the primary family of networking protocols currently used on the Internet. We will then see examples of how other people have built wireless networks to solve their communication problems, including diagrams of the essential network structure. Finally, we will present several common methods for getting your information to flow efficiently through your network and on to the rest of the world.

Networking 101
TCP/IP refers to the suite of protocols that allow conversations to happen on the global Internet. By understanding TCP/IP, you can build networks that will scale to virtually any size, and will ultimately become part of the global Internet. If you are already comfortable with the essentials of TCP/IP networking (including addressing, routing, switches, firewalls, and routers), you may want 27

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Chapter 3: Network Design

to skip ahead to Designing the Physical Network on Page 51. We will now review the basics of Internet networking.

Introduction
Venice, Italy is a fantastic city to get lost in. The roads are mere foot paths that cross water in hundreds of places, and never go in a simple straight line. Postal carriers in Venice