Data Communications and Networking with TCP/IP Protocol Suite

Citation

Forouzan, B. A. (2021). Data Communications and Networking with TCP/IP Protocol Suite (6th ed.). McGraw Hill.

Chapter Summary

The sixth edition, about 866 pages, has thirteen chapters, six appendices, a list of references and a glossary. According to the publisher, this edition was substantially restructured to reduce the number of chapters and to follow the organisation of the TCP/IP protocol suite more closely. The preface names two organising principles. First, networking is taught through protocol layering, because ideas such as addressing or framing and packetising recur at several layers and are better understood when each layer's treatment is compared. Second, the order is bottom-up: each layer is built on the services of the one below, so readers see how bits move at the physical layer before they see how programs exchange messages at the application layer. After the five layers come three chapters on wider topics.

Chapter 1: Introduction

An introduction to data communications and networking that defines protocol layering and gives a short description of both the TCP/IP protocol suite and the OSI model, the two reference frameworks used in the rest of the book.

Chapter 2: Physical Layer

The first layer of the suite. The preface says the chapter explains the relationship between data and signals, describes analog and digital signals, discusses multiplexing as a way to make use of available bandwidth, and finally goes below the physical layer to the transmission media themselves.

Chapter 3: Data-Link Layer

The second layer of the suite, concerned with communication across a single link between neighbouring nodes.

Chapters 4–6: Local Area Networks: LANs; Wide Area Networks: WANs; Connecting Devices and Virtual LANs

Three chapters on concrete network technologies: local area networks, wide area networks, and the devices that join network segments together, with virtual LANs.

Chapters 7–8: Network Layer: Data Transfer; Network Layer: Routing of Packets

The network layer receives two chapters, one on how data is carried from host to host across interconnected networks and one on how routes for packets are chosen.

Chapter 9: Transport Layer

Process-to-process delivery, the layer at which the Internet's transport protocols operate.

Chapter 10: Application Layer

The top layer of the suite, where programs exchange messages.

Chapters 11–13: Multimedia; Network Management; Cryptography and Network Security

The publisher describes these as the three concluding chapters that explore topics beyond the layers themselves: multimedia over networks, the management of networks, and cryptography with its use in network security.

Key Concepts

Chapter 1: Introduction

• Protocol layering: dividing the task of communication into layers, each providing services to the layer above.
• TCP/IP protocol suite: the layered set of protocols on which the Internet is based, used as the organising framework of the book.
• OSI model: the seven-layer reference model introduced for comparison with TCP/IP.

Chapters 2–6: Physical and Data-Link Layers and Network Technologies

• Data and signals: the distinction between information and its analog or digital representation on a medium.
• Multiplexing: sharing a link's bandwidth among several signals.
• Transmission media: the physical carriers below the physical layer.
• LANs, WANs and connecting devices: network technologies of different scale and the equipment, including virtual LANs, that joins them.

Chapters 7–10: Network, Transport and Application Layers

• Network-layer data transfer: carrying packets from source host to destination host across networks.
• Routing: choosing the paths that packets follow.
• Transport layer: delivery between processes on the communicating hosts.
• Application layer: the protocols through which programs exchange messages.

Chapters 11–13: Further Topics

• Multimedia networking: carrying audio and video over a network.
• Network management: monitoring and controlling a network's operation.
• Cryptography and network security: protecting communication across the layers.

Critical Analysis

Strengths

• Principles seen layer by layer. The preface's argument for teaching through layering is a genuine strength for beginners: recurring ideas such as addressing and framing are met several times, at different layers, so their common purpose becomes clear.
• A full bottom-up course. With separate chapters for the physical layer, the data-link layer, LANs, WANs and connecting devices before the network layer, the book gives five of its thirteen chapters to the layers below the network layer, with signals and media treated in their own right. This suits courses in electrical and electronic engineering and in information technology as well as in computer science.
• Two chapters on the network layer. Splitting data transfer from routing gives each topic room, which helps with the part of networking that students often find hardest.
• Reference apparatus. Six appendices, a reference list and a glossary support a reader new to the field.

Limitations

• Length. At about 866 pages the book holds more than one semester's material, and an instructor must choose what to cover in depth.
• Applications arrive late. In the bottom-up order, students reach the application layer only in Chapter 10. Readers who are motivated by familiar services such as the web or email, or courses with programming assignments, may prefer to begin at the top.
• Wide coverage, limited depth for advanced study. The last three chapters each condense a field (multimedia, management, security) into a single chapter; students who need detailed protocol behaviour or security will need further reading.

Where It Fits in the Course

Forouzan is the comprehensive, bottom-up introductory textbook of the networks course. Douglas Comer's The Internet Book is a much shorter, non-mathematical overview for readers without a technical background; read it before Forouzan to gain a mental map, or alongside it when the detail of the lower layers becomes hard to place. Kurose and Ross's Computer Networking: A Top-Down Approach covers the same five layers in the opposite order, starting from applications and using Internet protocols to motivate design choices; it is the main alternative if a course prefers to begin with the web and sockets. Tanenbaum, Feamster and Wetherall's Computer Networks follows the layered model from the physical layer upward, like Forouzan, and assumes some programming and operating-systems background, making it a natural second text.

For later study, Fall and Stevens's TCP/IP Illustrated, Volume 1 explains the Internet protocols by showing their behaviour in real packet traces and assumes an undergraduate networking course, so it fits after Chapters 7–10. Varghese and Xu's Network Algorithmics is a graduate text on making network software and hardware fast and lies well beyond this book.

How to Use This Book

The book suits first- and second-year students in computer science, information technology and electrical or electronic engineering taking a first course in data communications or networking. No prior networking knowledge is assumed in the publisher's description; general computer literacy and school mathematics are the reasonable starting points, and the signal material in Chapter 2 is easier with some comfort with graphs and basic algebra.

A practical plan:

• Foundation: Chapter 1, then Chapters 2 and 3. These give the vocabulary of layers, signals, media and frames on which everything later depends.
• Choose among Chapters 4–6. A computer-science course may cover LANs and connecting devices and skim WANs; an engineering or IT course may do all three.
• Core of the Internet: Chapters 7–10. Spend the most time on the two network-layer chapters and on the transport layer, which students meet again in every later networking course.
• Optional: Chapters 11–13 according to the course's aims. Chapter 13 makes a good bridge to a security course.

Because each layer builds on the one below, keep a one-page diagram of the five layers and note, for each chapter, which layer it covers and what service it offers upward. Pair the network-layer and transport-layer chapters with a packet-capture tool to watch real traffic, which makes the abstract protocol descriptions concrete.