An Overview of Techniques for Bandwidth Optimization

There are several general techniques for managing bandwidth in any type of computer network. Starting with an abstract model of a network with a congested link, this chapter looks at a variety of such techniques. The congested link is one that has more traffic required to flow on it than it has the capacity to carry. An expensive but simple approach is to add more capacity to the network to eliminate the congestion. Object caching is the technique of moving data objects so as to avoid traversing the congested link when accessing them. Compressing objects allows for reduction in the amount of data that needs to travel on the congested link. A variation on compression allows one to cache bytestreams and operate across multiple protocols. When several flows carrying the same content are flowing on the congested link, one can share content across all of these flows. Another technique is to modify some types of content (e.g., video) to a lower granularity resolution so as to reduce the amount of bytes required to transmit it. The use of rate control mechanisms provides for a fairer sharing of limited resources. Finally, dividing users into different categories and giving preference for one set of traffic over another provide for an alternative approach to deal with congested network links.