Quality of Service in Modern Packet Networks

Quality of Service in Modern Packet Networks: A Practical Technical Guide

Gary Hallberg’s Quality of Service in Modern Packet Networks sets out how packet-based networks evolved from best-effort delivery into infrastructures capable of supporting voice, video, and other demanding applications. Rather than treating QoS as a single feature, the book follows the technologies and architectural ideas that developed to manage delay, loss, jitter, and bandwidth in modern telecommunications networks.

Published in 2019, the first edition is aimed at readers who have a basic grasp of Ethernet and packet networking but want a clear path into QoS concepts. A review chapter at the beginning reinforces essential material such as the OSI model, IP addressing, routing, Ethernet, MPLS, switches, and routers, making the book accessible to students while still offering depth for working professionals.

From Circuit Switching to Packet-Based Service Quality

The early chapters place QoS in context. Circuit-switched networks carried their own guarantees; packet networks traded some of that predictability for scalability and cost efficiency. Hallberg explains why real-time and loss-sensitive traffic is challenging over packet infrastructure and how technologies such as Frame Relay, ATM, Integrated Services, and Differentiated Services attempted to close the gap. The chronological approach helps readers understand not only what each technology does but why some approaches gained traction and others faded.

Core QoS Mechanisms and Architectures

• Integrated Services and RSVP: resource reservation, admission control, policy control, classification, packet scheduling, and dropping.
• Packet classification: Ethernet frame classification, IPv4 precedence, the Differentiated Services field, IPv6 traffic class, and MPLS.
• Queuing and scheduling: FIFO, priority queuing, weighted round robin, weighted fair queuing, class-based WFQ, and combined priority/class-based approaches.
• Congestion avoidance: mechanisms that help networks manage overload before performance collapses.

These chapters give readers a vocabulary for QoS design and show how classification, marking, queuing, and scheduling work together rather than as isolated features.

Layer 2, SD-WAN, and Traffic Engineering

The book also examines QoS beyond Layer 3. It covers Layer 2 Ethernet networks and the Metro Ethernet Forum, including two-rate/three-color metering, single-rate/three-color metering, MEF 10.3 policing, and color-aware versus color-blind modes. Later chapters turn to SD-WAN environments and forward error correction, then to traffic engineering with MPLS RSVP-TE, CSPF, MPLS-TP, and Segment Routing.

This span is useful because modern service providers rarely rely on a single QoS tool. The material connects traditional carrier Ethernet and MPLS operations with newer software-defined approaches to network transformation.

Measuring QoS Against Service-Level Agreements

Delivering QoS is only half the story; providers also need to prove it. Hallberg devotes a chapter to measurement technologies, including Remote Network Monitoring (RMON), Cisco NetFlow and IPFIX, RFC 2544 throughput testing, Y.1564 Ethernet service activation, Y.1731 OAM functions, and the IETF Two-Way Active Measurement Protocol (TWAMP). For engineers working with SLAs, this section links design intentions to observable network performance.

Who Will Find This Book Useful

Quality of Service in Modern Packet Networks is written for students, network engineers, telecommunications professionals, and technical readers who want a structured introduction to QoS in packet networks. A basic understanding of Ethernet and packet technologies is assumed, but the opening review chapter provides a foundation for newcomers. The glossary and summary at the end make it suitable for reference as well as sequential study.

If you work with carrier networks, service provider infrastructure, enterprise WANs, or network design, this first edition offers historical context and practical architecture in one volume.