ABSTRACT
Flexible and reliable bandwidth allocation is one of the key features of Asynchronous transfer mode (ATM). In terms of bandwidth allocation capability, ATM represents a somewhat more rational approach with respect to both ends of the spectrum. This chapter discusses how ATM manages bandwidth allocation, types of bandwidth allocation strategies and bandwidth allocation classes. The virtual path and virtual channel mechanisms allow allocation of bandwidth to each user at a very fine granularity so that the available bandwidth of the physical medium is utilized very efficiently. The chapter looks at the traffic classes offered by ATM to handle different bandwidth demands. ATM defines the set of traffic classes and traffic parameters to characterize incoming traffic. The traffic classes include constant bit rate, variable bit rate (VBR), available bit rate and unspecified bit rate. The VBR service class is used for handling bursty with varying bandwidth usage over time.
