Windows 2000 Performance Guide

Internet Protocol Layer

The Internet Protocol (IP) layer, also known as Layer 3 (with the physical and data link layers associated with the MAC layer being Layers 1 and 2, respectively) is primarily concerned with delivering packets from one location to another. The technology that the Internet protocol implements is called routing. Routing is associated with a bundle of standards that include IP itself, ICMP, ARP, BGP, and others. Another important function of the IP layer is to make larger packets conform to the MTU of the underlying data link and physical layer protocol and transmission medium. In this section, we introduce the key aspects of IP routing technology that most impact network performance and capacity planning.

You will find that the basic technology used in IP routing is deceptively simple. What makes IP routing such a difficult topic from a performance perspective is the complicated, interconnected network infrastructures and superstructures that organizations have erected to manage masses of essentially unscheduled IP traffic. That the Internet works as well as it does is phenomenal, given the complexity of the underlying network of networks it supports. While there are many good books available on TCP/IP and how it works, there are not many places where a Windows 2000 system administrator can gain a good appreciation for the major performance and capacity issues facing organizations that rely on the Internet for mail, file transfer, e-commerce, and other data ...