Chapter 7 - Network Layer — Building on IP

Abstract

This chapter discusses network-layer building on Internet Protocol (IP). The purpose of the network layer is to help route messages between different local networks. Central to this layer is the concept of exclusive network addresses, where every terminal connected to the network has its own uniquely assigned address. One of the most common protocols in this layer is the IP, used worldwide throughout the internet. The IP is so adaptable that it has become a common denominator in many communication environments. On its own, IP is a simple, effective, and well-tested protocol for carrying blocks of data. The basic IP packet format consists of a header followed by a payload. The header can be between 20 and 60 bytes in length, and is always a multiple of 4. It contains various data fields relevant to the protocol being transported, its operation and management. Internet protocol checksum calculation could be by far the most often performed piece of software or firmware subroutine function in the whole world. The way current IP options are encoded have been improved to allow for greater flexibility and to provide a more flexible approach for further options in the future. User diagram protocol is a very versatile protocol, and ideal for small embedded systems when used in applications such as data logging, batch transfers, or even general purpose communications.