6 - Internet Protocol Overview

Abstract

This chapter briefly introduces the various protocols that are associated with TCP/IP networks. This includes required protocols such as IP or TCP, as well as recommended and other commonly used protocols. Internet protocols are presented in seven categories, beginning with the network interface and moving up through the IP internetworking model to the application layers; special attention is given to three other categories: protocols related to Integrated Services (intserv) and Differentiated Services (diffserv), different mechanisms for delivering network services; internet security protocols; and internet management protocols. Each section introduces one of these categories, describes what protocols within the category do, and includes lists of all relevant protocols with brief descriptions. At the network interface or network link layer, network protocols define how nodes actually exchange data across network media, but the protocols also provide for mechanisms by which data can cross network boundaries. The internet layer provides a mechanism through which disparate networks can be linked through a logical, rather than a physical, internet structure. By imposing this virtual network architecture over the many different and interconnected literal network architectures, processes anywhere within the virtual network can communicate with each other. By enabling processes to communicate, applications can exchange information, thus enabling users to get value from using the global internet. This chapter also touches on some of the important issues facing the internet, including network security, network performance, and network management.