IP Quality of Service

This is a fabulous book if you want to know how the Qos mechanisms work. This guy is a degreed engineer, not somebody who has a B.S. in B.S. and is in a job called "engineer". And his book reflects that. That said, there are a few points to be made. This isn't a configuration book...it's a "nuts and bolts" book. Try the W. Odom book for configuration. Also, this book is rapidly becoming outdated. Policing explains CAR, but CAR is outdated in favor of Class Based Policing, which doesn't work the same way as CAR at all! Get the Odom book first. If you're still curious about the nuts and bolts, buy this one.

After reading the book and reading the comments of the reviewers, I am surprised that there are so many negative comments on the book. Personally, I find the book extremely useful in understanding the QoS implemenation of Cisco box. A lot of the algorithm and implementation details of the QoS functions inside a Cisco router is reviewd here in the book and although the Cisco web site may provide you a lot more information on how to configure the router, most documents does not tell you the inside story on how the mechanisms work like what this book does.....my 2 cents.

For those who need a general overview of how QoS is implemented in Cisco devices and software, this book would serve as a pretty good introduction. Some of the discussion is generic enough to be useful to those who are interested in QoS, but not necessarily implemented in a Cisco environment. Naturally then the reader is assumed to have a good background in Cisco network architectures. The author implements case studies in the book, with it being assumed that the reader is also comfortable with the actual administration of Cisco network devices. Therefore the book is really useful for those readers who are involved in the practical implementation of QoS schemes. Those interested in developing new approaches to QoS may still find the book helpful as an introduction to what is known. There are more specialized treatments that can be found online if one is willing to spend the time finding and downloading the documents (from the Cisco website). I only read the first six chapters of the book, which deal with IP QoS, and so my review will be restricted to these. Remembering that the Internet is a best-effort service only, the author introduces the IP QoS functions in chapter 1. The advent of voice and video traffic over IP for example, requires the need for QoS in modern networks. QoS services are divided into levels: best-effort, which does not guarantee traffic delivery; differentiated service, which groups traffic into classes but does not guarantee its delivery; and guaranteed service, which allocates network resources to ensure specific service requirements. Bandwidth, packet latency, and packet loss are measures used to characterize connection performance. Chapter 2 gives a more detailed overview of the differentiated services architecture for delivering QoS on the Internet. Called `diffserv' by the IETF, the author discusses the historical origins of it, and how it provides traffic differentiation by breaking traffic up into a small number of classes, with relative service priority existing among these classes. The presentation is straightforward to follow, once one gets used to remembering all of the many acronyms that are employed, such as PHB (per-hop behavior), DSCP (Differentiated Services Code Point), etc. The traffic conditioners, which are QoS functions that set the DSCP field and monitor traffic for profile compliance, and discussed in detail. Network provisioning, signaled QoS, and QoS policy manager are all discussed as resource provisioning policies. In chapter 3, the author overviews the use of traffic conditioning functions at the network boundary as a tool for providing differentiated services. In one, called `packet classification', the packets are identified using one or more fields in a packet. This could be the MAC address, URL, IP Precedence, etc. Then `packet marking' is used to mark classified packets according to their traffic class. Traffic rate management, another conditioning function, is discussed via the token buc

IP QoS is here to stay and grow, so is Internet. But there has not been a fine book that explains and teaches various aspects of it such as CAR, WFQ, RSVP, etc...until this one. The author did a good job to help us understand these concepts and provides plenty of examples in Cisco IOS language. Remember these are NOT easy concepts to master unless you read this book.

If you want to understand the mysteries of IP QOS and/or need to implement QOS in a Cisco environment, this book is an absolute must have. The writing is crystal clear. Srinivas provides the kind of examples and illustrations that can make fairly complex concepts understandable to anyone who needs to make the most of their networks and support time-critical applications. Virtually every topic includes detailed configs using the latest Cisco IOS. An excellent balance of theory and practical guidance. Very well edited considering its timeliness. Grenville Armitage's "Quality of Service in IP Networks" also deserves a place on your bookshelf, but if you have to choose, "IP QOS" is the one to get.