What's new in the 8th edition?

We think one important reason for the success of our book has been that it continues to offer a fresh and timely approach to computer networking instruction. We’ve made changes in this eighth edition, but we’ve also kept unchanged what we believe (and the instructors and students who have used our book have confirmed) to be the most important aspects of this book: its top-down approach, its focus on the Internet and a modern treatment of computer networking, its attention to both principles and practice, and its accessible style and approach toward learning about computer networking. Nevertheless, the eighth edition has been revised and updated substantially.

Readers of earlier editions of our book may recall that in moving from the 6th to the 7th edition, we deepened our coverage of the network layer, expanding material which had been previously covered in a single chapter into a new chapter focused on the so-called “data plane” component of the network layer (Chapter 4) and a new chapter focused on the network layer’s “control plane” (Chapter 5). That change turned out to be prescient, as software-defined networking (SDN), arguably the most important and exciting advance in networking in decades (along with 4G/5G networks), has been rapidly adopted in practice—so much so that it’s already hard to imagine an introduction to modern computer networking that doesn’t cover SDN. SDN has also enabled new advances in the practice of network management, which we also cover in modernized and deeper detail in this edition. And as we’ll see in Chapter 7 of this 8th edition, the separation of the data and control planes is now also deeply embedded in 4G/5G mobile cellular network architectures, in its “all-IP” approach to 4G/5G core networks. The rapid adoption of 4G/5G networks and the mobile applications they enable are undoubtedly the most significant changes we’ve seen in networking since the publication of our 7th edition. We’ve thus significantly updated and deepened our treatment of this exciting area. Indeed, the ongoing wireless network revolution is so important that we think it's become a critical part of an introductory networking course.

In addition to these changes, we’ve also updated many sections throughout the book and added new material to reflect changes across the breadth of networking. In some cases, we have also retired material from the previous edition. As always, material that has been retired from the printed text can always be found on our book’s Companion Website. The most important changes in this 8th edition are the following:

• Chapter 1 has been updated to reflect the ever-growing reach and use of the Internet, and of 4G/5G networks.
• Chapter 2, which covers the application layer, has been significantly updated, including material on the new HTTP/2 and HTTP/3 protocols for the Web.
• Chapter 3 has been updated to reflect advances in, and evolution in use of, transport-layer congestion control and error control protocols over the past five years. While this material had remained relatively stable for quite some time, there have been a number of important advances since the 7th edition. Several new congestion-control algorithms have been developed and deployed beyond the “classic” TCP algorithms. We provide a deeper coverage of TCP CUBIC, the default TCP protocol in many deployed systems, and examine delay-based approaches to congestion control, including the new BBR protocol, which is deployed in Google’s backbone network. We also study the QUIC protocol, which is being incorporated into the HTTP/3 standard. Although QUIC is technically not a transport-layer protocol—it provides application-layer reliability, congestion control, and connection multiplexing services at the application layer—it uses many of the error- and congestion-control principles that we develop in the early sections of Chapter 3.
• Chapter 4, which covers the network-layer data plane, has general updates throughout. We’ve added a new section on so-called “middleboxes,” which perform network-layer functions other than routing and forwarding, such as firewalling and load balancing. Middleboxes build naturally on the generalized “match plus action” forwarding operation of network-layer devices that we cover earlier in Chapter 4. We’ve also added timely new material on topics such as the amount of buffering that is “just right” in network routers, on net neutrality, and on the architectural principles of the Internet.
• Chapter 5, which cover the network-layer’s control plane, contains updated material on SDN, and a significantly new treatment of network management. The use of SDN has evolved beyond management of packet-forwarding tables to include configuration management of network devices as well. We introduce two new protocols, NETCOF and YANG, whose adoption and use have fueled this new approach toward network management.
• Chapter 6, which covers the link layer, has been updated to reflect the continuing evolution of link-layer technologies such as Ethernet. We have also updated and expanded our treatment of datacenter networks, which are at the heart of the technology driving much of today’s Internet commerce.
• As noted earlier, Chapter 7 has been significantly updated and revised to reflect the many changes in wireless networking since the 7th edition, from short-range Bluetooth piconets, to medium-range wireless 802.11 local area networks (WLANs), to wide-area 4G/5G wireless cellular networks. We have retired our coverage of earlier 2G and 3G networks in favor of a broader and deeper treatment of today’s 4G LTE networks and tomorrow’s 5G networks. We have also updated our coverage of mobility issues, from the local issue of handover of mobile devices between base stations to the global issue of identity management and mobile device roaming among global cellular provider networks.
• Chapter 8, which covers network security, has been updated to reflect changes in wireless network security in particular, with new material on WPA3 security in WLANs, and mutual device/network mutual authentication and confidentiality in 4G/5G networks.