TABLE OF CONTENTS After having discussed several commercial platforms, systems architectures, and network processors, we have examined most of the necessary components a systems designer requires in order to put together a working switching/routing system. These include network processors, classification and forwarding processors, search engines, and switch fabrics. In this chapter, we turn our attention to the last important piece of this architectural jigsaw puzzle-traffic managers.
In some networking realms, not all transmitted packets can be treated in the same way for profitability and efficiency reasons. As a result, different classes of service (CoS) must implement differentiated levels of quality of service (QoS) as expected for each packet that traverses the network. This QoS framework reflects the potential critical, important, urgent, lucrative, or undesirable nature of specific packets. Traffic management is a wide conceptual area of network processing that deals with how the underlying flow of real-time traffic, which can be composed of a continuous, massive, and time-varying collection of disparate and largely unrelated session packets from a staggering multitude of applications, must be treated in order to implement, monitor, and enforce specific QoS requirements of the network.
As we have seen in the first 10 chapters of the book, most powerful network processors already contain certain embedded capabilities that enable them to perform in some cases adequate and in other cases rudimentary traffic management operations on the traffic stream that they monitor and process. However, in...
