Data Communication and Computer Networks Tutorial (3rd Edition)

Author: William A. Shay
Publisher:
Publish Date: 2005-01-01
Features: This book systematically introduces the fundamental theories and applications in the fields of data communications and computer networks. Compared with the previous two editions, the third edition has significant updates in both content and organization, placing greater emphasis on the integration of theory and practical application. The main contents include: transmission media and data encoding, analog and digital signals, establishing connections, data compression, data integrity, data security, flow control, local area networks, network interconnection, Internet protocols and applications, Internet programming, and circuit technology, etc. Additionally, each chapter is accompanied by a large number of review questions and exercises. This book is suitable as a textbook and reference for computer science majors in higher education institutions and can also be used as a reference for professionals in related fields. This book systematically introduces the fundamental content in the field of data communications and computer networks. Compared with the previous two editions, the third edition has significant updates in both content and organization. The book inherits the strengths of the previous two editions, such as systematic theoretical structure, concise and easy-to-understand narrative language, and selected review questions and exercises at the end of each chapter. At the same time, it places greater emphasis on combining with practical applications beyond the introduction of fundamental theories. For aspects that are relatively important in applications, such as data compression, data integrity, data security, and flow control, separate chapters are dedicated to detailed explanations. Furthermore, the content related to Internet protocols and applications, and Internet programming has been greatly enriched, making the book not only a theoretical textbook but also highly practical for guidance. This book systematically introduces the fundamental theories and applications in the field of data communications and computer networks. Compared with the previous two editions, the third edition has significant updates in both content and organization, placing greater emphasis on the integration of theory and practical application. The main contents include: transmission media and data encoding, analog and digital signals, establishing connections, data compression, data integrity, data security, flow control, local area networks, network interconnection, Internet protocols and applications, Internet programming, and circuit technology, etc. Additionally, each chapter is accompanied by a large number of review questions and exercises. This book is suitable as a textbook and reference for computer science majors in higher education institutions and can also be used as a reference for professionals in related fields. This book systematically introduces the fundamental content in the field of data communications and computer networks. Compared with the previous two editions, the third edition has significant updates in both content and organization. The book inherits the strengths of the previous two editions, such as systematic theoretical structure, concise and easy-to-understand narrative language, and selected review questions and exercises at the end of each chapter. At the same time, it places greater emphasis on combining with practical applications beyond the introduction of fundamental theories. For aspects that are relatively important in applications, such as data compression, data integrity, data security, and flow control, separate chapters are dedicated to detailed explanations. Furthermore, the content related to Internet protocols and applications, and Internet programming has been greatly enriched, making the book not only a theoretical textbook but also highly practical for guidance. Preface This book is translated from William A. Shay's "Understanding Data Communications Networks (Third Edition)" (Brooks/Cole Publishing Inc., 2004). The first edition was published nine years ago, and the second edition was published five years ago. It systematically introduces the fundamental content in the field of data communications and computer networks and has been adopted by many universities in the United States as a textbook. After the second edition was published, significant changes occurred in the field of data communications and computer networks, and the third edition reflects these changes. Compared with the previous two editions, the third edition has significant updates in both content and organization. At the same time, it places greater emphasis on combining with practical applications beyond the introduction of fundamental theories. For aspects that are relatively important in applications, such as data compression, data integrity, data security, and flow control, separate chapters are dedicated to detailed explanations. Additionally, the content related to Internet protocols and applications, and Internet programming has been greatly enriched. New or expanded content includes transmission media, DSL technology, Universal Serial Bus (USB) and FireWire (IEEE 1394 standard) protocols, Synchronous Optical Network (SONET), Frame Relay protocols, gigabit and ten-gigabit Ethernet standards, 802.11 wireless LAN standards, switched Ethernet, virtual LANs, classless inter-domain routing, multicast, quality of service, Real-Time Transport Protocol (RTP), compression techniques, Advanced Encryption Standard (AES) and Rijndael algorithm, Pretty Good Privacy (PGP) secure programming, Secure Sockets Layer (SSL), IPSec, Transport Layer Security (TLS), X.509 certificates, firewalls, security threats, and CGI programming, etc. The book inherits the strengths of the previous two editions, such as systematic theoretical structure, concise and easy-to-understand narrative language, and selected review questions and exercises at the end of each chapter. Review questions help readers review the important content of each chapter, while exercises focus on applying the learned knowledge to solve practical problems. References up to 2003 are listed at the end of each chapter. The book also includes explanations of data communication and network terminology and commonly used acronyms at the end. The book serves as both a theoretical textbook and a highly practical guide. It can be used as a textbook and teaching aid for related courses in computer science at higher education institutions and also as a reference book or for self-study and training for professionals in this field. This book was translated under the leadership of Professor Gao Chuanshan from Fudan University, who translated Chapters 1, the glossary, and the abbreviations. Li Junwei translated Chapters 2, 3, and 4, Chen Qi translated Chapters 5, 6, and 7, Xu Dan translated Chapters 8, 9, and 10, and Qu Guang translated Chapters 11, 12, and 13. Finally, Professor Gao Chuanshan compiled and proofread the book. Due to time and limitations, there may be some inaccuracies, and we sincerely welcome your feedback. Translator Department of Computer Science and Engineering, Fudan University, Summer 2004 Author Bio Gao Chuanshan was born in 1942 and graduated from Fudan University in 1963. He was a visiting scholar at the Department of Computer Science, University of Illinois (UIUC) from 1981 to 1983. He is currently the Vice Dean of the School of Technology Science and Engineering, Professor and Doctoral Supervisor at the Department of Computer Science and Engineering, Director of the Computer and Communication Laboratory, and also serves as a member of the National Computer Rank Examination (NCRE) Committee of the Ministry of Education. He has long been engaged in teaching and research on computer systems, software, and applications, with expertise in data communications, computer networks, and distributed systems and their applications. He has published more than 140 papers in academic journals and conferences and more than 20 books. His scientific and technological achievements have won three first prizes, two second prizes, and three third prizes at provincial and ministerial levels of scientific and technological progress. Since 1992, he has been enjoying special allowances from the State Council of the People's Republic of China. In 1993, he won the third prize of the Guohua Science and Technology Fund Award. In 1995, he was named an Outstanding Educator of Shanghai. In 1999, he won the third prize of the Shanghai Municipal People's Government Decision-Making Research Achievement Award. In 2002, "Data Communications and Computer Networks" won the first prize of the National Excellent Textbook Award for Higher Education. To date, he has trained 66 master's students, 19 doctoral students, and 3 postdoctoral researchers, of whom 46 have obtained master's degrees, 10 have obtained doctoral degrees, and 2 have completed their postdoctoral research. William A. Shay received his Ph.D. from the University of Wisconsin-Milwaukee in 1978 and is currently a Professor and Chair of the Department of Information and Computer Science at the University of Wisconsin-Green Bay. He is dedicated to curriculum development and textbook writing. In addition to this book, he has also written "Introduction to Operating Systems." Purpose The second edition of this book was published five years ago, but in recent years, significant changes have occurred in the field of data communications and computer networks. For example: The number of Web-based software has been increasing. The demand for secure connections for Web sites has become widespread. Higher security requirements and more tools to handle security threats have emerged. New encryption standards have emerged, and older standards are gradually being phased out. Quality of Service (QoS) issues have led to the need for new protocols. New connection technologies (such as DSL, USB, and FireWire) have become very common. Ethernet has been extended to gigabit speeds. The emergence of audio compression modes like MP3 and computer games has completely changed the way people use the Internet. Wireless technology has replaced traditional technologies in many aspects. Some protocols that were once commonly used or considered promising are now rarely used. The world is no longer the same as when the previous edition was published, and the new edition reflects these changes. Although most of the content has changed, the goal remains basically the same. It is written for undergraduate computer science students who have completed at least two semesters of software design courses and have the necessary knowledge for discrete mathematics and calculus. The book covers the content of introductory courses on data communications and computer networks, such as transmission media, analog and digital signals, data transmission, compression and encryption methods, network topology, network security, LAN protocols, Internet-based protocols and applications, circuit-switching technology, and Web applications, etc. The book mainly includes the following content: Differences and advantages/disadvantages of various transmission media. Analog and digital signals, modulation and demodulation techniques, and how modulating devices such as modems, cable modems, and DSL modems work. The impact of transmission noise on protocols and how they detect corrupted information. How protocols handle information corruption or loss caused by noise. Standards (such as AES, ATM, DES, EIA-232, HDLC, IEEE 802.3, IEEE 802.5, IEEE 802.11, IPv6, JPEG, MP3, MPEG, OSI, SONET, TCP/IP, X.25) and standardization organizations, and why these standards are needed. Data compression techniques, types of data that can be compressed, and comparisons of different compression techniques. Worms, viruses, and other threats to network computers. The need for security and the effectiveness of various encryption methods. The differences between public key encryption systems and private key encryption systems. How to establish secure connections to remote stations. The need for flow control and various implementation methods. LAN protocols and competition strategies on shared transmission media. Wireless standards. Methods of connecting LANs. Routing strategies. The need to support real-time video applications and the response to Quality of Service (QoS) issues. How to design and build practical client/server applications. How increasing Web usage and multimedia applications are affecting existing protocols and the work being done to address these issues. Content and Structure Many changes have been made to the content of the third edition, some based on reader feedback and others based on technological advancements. Some figures have been made clearer and more understandable, and the descriptions of many protocols have been improved. Additionally, some topics that are becoming increasingly common have been expanded to include new developments and removed some topics that are no longer as important in the field. A significant change is the reorganization of the book into 13 chapters, as follows: Chapter 1: Communication, Standards, and Protocols Introduction Chapter 2: Transmission Media and Data Encoding Chapter 3: Analog and Digital Signals Chapter 4: Establishing Connections Chapter 5: Data Compression Chapter 6: Data Integrity Chapter 7: Data Security Chapter 8: Flow Control Chapter 9: Local Area Networks Chapter 10: Network Interconnection Chapter 11: Internet Protocols and Applications Chapter 12: Internet Programming Chapter 13: Circuit Technology This reorganization makes teaching easier and allows instructors to select specific topics to meet course requirements. Some chapters correspond to parts of chapters in the previous edition, while others are combinations of different chapters from the previous edition. Of course, many chapters contain a lot of new material. A major change is the inclusion of many new or expanded topics, such as: Transmission media, including metallic conductors, fiber optics, wireless, and satellite communications. DSL technology. Universal Serial Bus (USB) and FireWire (IEEE 1394 standard) protocols. Synchronous Optical Network (SONET). Arithmetic compression, fax compression, and MP3 compression techniques. Advanced Encryption Standard (AES) and Rijndael algorithm. Pretty Good Privacy (PGP) secure programming. Secure Sockets Layer (SSL), Transport Layer Security (TLS), and X.509 certificates. Firewalls. Security threats. Ethernet, fast Ethernet, gigabit Ethernet standards, and ten-gigabit Ethernet standards. 802.11 wireless LAN standards. Switched Ethernet. Virtual LAN. Third and fourth layer protocols, including classless inter-domain routing, routing and routers, multicast, quality of service issues, Real-Time Transport Protocol (RTP), and IPSec. Internet applications. Project-based CGI programming, including practical examples of Web-based ordering systems using Linux and Perl scripts. Frame Relay protocols. Although it is difficult (almost impossible) to cover all these topics in a single semester course, the wide range of topics allows instructors to choose flexibly based on their needs. The book combines theory and application. Theory provides a solid foundation for further study, while applications bring students closer to the realities of communication systems and networks and provide them with valuable experience. All students will benefit from the applications, while the more theoretical material challenges ambitious students. Additionally, Chapter 12 provides practical models of client/server applications that students can build themselves. Each chapter builds on the next. For example, when learning about multiplexing, competition, or compression, students need to understand how signals propagate through different media. When learning about LANs, they need to understand the competition issues on multi-access lines, noise channels, and flow control. When learning about wide-area network protocols, they need to understand LAN protocols and why they are not suitable for larger networks. A summary of the specific content of each chapter is as follows: Chapter 1 introduces the field of communication and networks, covering current issues and applications in this field. It describes the need for standards, lists relevant standardization organizations, and summarizes the long-standing protocol model—Open Systems Interconnection. The chapter concludes with an outlook on the future. Chapter 2 presents different types of transmission media (cables, wired, wireless, satellite, and fiber optics), their advantages and disadvantages, and various methods of encoding data. Chapter 3 provides an in-depth introduction to analog and digital signal types, the modulation techniques for converting between them, and the impact of noise on bit rates. It also discusses modems, cable modems, and DSL technology. Chapter 4 focuses on establishing connections (i.e., transmission methods), communication carriers (telephone systems, SONET, and T1), interface standards (EIA-232, USB, and FireWire), and how multiple devices access the same medium (multiplexing methods and various competition protocols). Chapter 5 covers compression techniques suitable for compressing different types of data and how they identify different types of redundancy in data. Chapter 6 discusses the issue of data integrity when sending data, including error detection and error correction techniques such as check bits, cyclic redundancy checks, and Hamming codes. Chapter 7 discusses data security, including encryption techniques (public key and private key), encryption standards, key exchange algorithms, authentication methods, X.509 certificates, and secure connections. Firewalls and various threats (viruses, worms, hackers, and denial-of-service attacks) are also discussed. Chapter 8 introduces flow control algorithms, outlines how devices handle information exchange and lost or damaged data, and also introduces formal methods for verifying the correctness of protocols. Chapter 9 describes LAN protocols, including different versions of Ethernet (original, fast Ethernet, and gigabit Ethernet), token ring networks, and IEEE 802.11 wireless LAN standards. Chapter 10 introduces methods of connecting various networks, covering second-layer connections (bridges and switches), address learning, spanning tree algorithms, switched Ethernet, and virtual LANs. Additionally, it introduces third-layer connections and discusses various routing algorithms (Dijkstra, Bellman-Ford, RIP, and BGP, etc.). The chapter also describes issues caused by network congestion and deadlock. Chapter 11 explores Internet-related issues, introducing the Internet Protocol (IP) versions 4 and 6 and Quality of Service (QoS) issues. Multicast and other protocols designed to provide real-time services for the Internet are also introduced. Additionally, TCP (connection management, flow control, and congestion management) is summarized, and some common Internet applications (Telnet, SSH, FTP, and SMTP) are introduced. Chapter 12 is written for instructors who want to introduce student projects into their courses. This chapter provides practical examples of client/server applications, including socket programming and CGI (Common Gateway Interface) programming using C and Perl scripts, along with sample code for file transfer, search engines, and online ordering systems. Chapter 13 introduces circuit-based technologies such as ISDN, X.25, Frame Relay, and ATM. The questions at the end of each chapter are divided into two parts. The first part is review questions, and the answers can all be found directly in the corresponding chapters. These questions encourage readers to review the text and identify the important content that the author or teacher considers significant. I believe this method is better from a teaching perspective than simply listing key points at the end. It encourages students to read the textbook sequentially, like reading a novel. However, reading complex material often requires reading it multiple times and then returning to the textbook to understand different concepts. A colleague once told me about her conversation with a student who was struggling with extra-curricular assignments. This student worked part-time and decided not to study in a tedious and boring way. Instead, he took the book to work with him and read it whenever he had a chance. Later that semester, his grades improved. He told the teacher that he only started to truly understand the material after reading it five or six times. Review questions alone are not enough. The second part is exercises, which require readers to apply and compare the knowledge they have learned, make logical reasoning, and consider other possible solutions. The answers to the exercises are not always simple statements that can solve the problem, but require in-depth analysis. However, this is closer to typical real-world problems. Supplementary Materials The related website for this book is http://www.uwgb.edu/shayw/udcn3, and the website provides a wealth of supplementary materials to facilitate teaching. Acknowledgments Very few tasks, such as writing a textbook, can be completed by one person alone. Many people have provided me with a great deal of help and given me valuable suggestions and support. I am particularly grateful to the following people for giving me many good suggestions in the previous two editions: Abdullah Abonamah, Akron University, James E. Holden, Clarion University, David Kieper, University of Wisconsin-Green Bay, David Whitney, San Francisco State University, George W. Ball, Alfred University, Dr. Subramakrishnan, Bowling Green State University, Lance Leventhal, J. Archer Harris, James Madison University, Mehran Basiratmand, Florida International University, Dr. Seyed H. Roosta, Mount Mercy College, Judith Molka, University of Pittsburgh, Dr. Paul N. Higbee, North Florida University, Ron Bates, De Anza College, Dr. Brit Williams, Kenyon State University, Dan O'Connell, Fredonia College, SUNY, Dr. Gene H. Hill, Old Dominion University, Bruce Derr, Jon L. Spear, Syracuse University, Stan Wine, Hunter College, and New Era of Networks company, Mohammad El-Soussi, Santa Barbara City College, Dr. J. Mark Pullen, George Mason University, Janet M. Urlaub, Sinclair Community College. I would like to thank those who took the time to review the manuscript of the third edition and those who provided valuable suggestions for modifying the second edition. I carefully reviewed all the comments and suggestions, and many of them were included in the final draft. I would like to thank the reviewers of this edition: Irvin Jay Levy, Gordon College, Mark Pullen, George Mason University, Aby Tehranipour, Eastern Michigan University, Camelia Zlatea, DePaul University. I would like to thank all the people at Brooks/Cole Publishing Company, including editor Kallie Swanson and assistant editor Aarti Jayaraman. I would like to thank Penmarin Books for managing the publishing process, Cindy Kogut for copyediting the manuscript, and George Barile of Accurate Art for writing the descriptions for the new edition. It is their efforts that turned a manuscript into a book. At the same time, I would like to thank my family—Judy, Dan, and Tim—for their help, which allowed me to have "free time" to write. Finally, I would like to thank all the readers of this book. I welcome any comments and can be sent to William A. Shay, Department of Information and Computing Sciences, University of Wisconsin-Green Bay, Green Bay, WI 54311-7001, or via email to shayw@uwgb.edu. William A. Shay