Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.

Bandwidth management is about making sure that enough bandwidth is available to meet traffic needs, and if not, managing the traffic in some way to ensure that critical traffic gets through. There are a number of topics that deal with bandwidth management. Refer to the following topics for more information:

• QoS (Quality of Service)    This is the major topic that covers the many ways that users and services are provided enough network bandwidth to ensure that data is delivered with minimal delay and packet loss.


• CoS (Class of Service)    CoS is a level of service that is promised to a client, not to be confused with QoS (quality of service). For example, you may choose next-day service from an express package service. That is a class of service. But the package may not arrive on time due to poor quality of service. You deserve a refund since the class of service you requested was not delivered.


• Congestion Control Mechanisms    This topic discusses why networks, especially packet-switched networks, cannot always deliver COS or QoS, even when adequate bandwidth appears to be available.


• Differentiated Services (Diff-Serv)    This topic covers work being done in the IETF Diff-Serv working group to define IP bandwidth management schemes using COS. In particular, the group is defining how to use the ToS (type of service) byte in the IP packet to identify prioritization of traffic.


• Multimedia and Multimedia Networks    This topic is not about bandwidth management, but it talks about why you are going to need it.


• Policy-Based Management    If bandwidth has to be allocated to specific users and applications in a fair (or unfair way), policies must be created to define who or what gets bandwidth and when. This topic describes how bandwidth is managed according to policies.


• Traffic Management, Shaping, and Engineering    The best example of traffic management and "shaping" is to use the analogy of how traffic management is done on crowded freeways. At on ramps, traffic lights may admit cars every few seconds in order to space them out and distribute the "load" on the freeway.


• Load Balancing    With load balancing, redundant network links and/or network services are provided to spread loads across redundant links or systems. At a Web site, traffic may come in over multiple aggregate links to a load-balancing system that will hand packets off to the least busy server or a server that is most appropriate for processing the packet.


• VPN (Virtual Private Network)    A VPN is a tunneling technique that may provide QoS in some network environments. Protocols such as MPLS are meant to provide that over the Internet.

Finally, there are some topics that discuss how to build high-bandwidth networks, either in the enterprise or on the Internet. These topics include "Backbone Networks," "High-Speed/High-Performance Networking," "Link Aggregation," "MPLS (Multiprotocol Label Switching)," "Multilayer Switching," "Network Core Technologies," "Network Design and Construction," "NPN (New Public Network)," "Optical Networks," "Switch Fabrics and Bus Design," and "Switching and Switched Networks."

Copyright (c) 2001 Tom Sheldon and Big Sur Multimedia.
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