Charging and Accounting for Bursty Connections

Statistical sharing over several timescales is a key feature of the Internet, and is likely to be an essential aspect of future ATM networks. In this chapter we describe how usage-sensitive pricing can encourage statistical sharing, and we provide a quantitative framework for the discussion of pricing issues in systems where statistical sharing is important. In particular we describe a simple charging and accounting mechanism for real-time bursty connections, based on the concept of an eeective bandwidth. The mechanism performs the dual role of conveying information to the network that allows more eecient statistical sharing, and information to the user about the resource implications of diierently policed connection requests. The resulting tarii takes a strikingly simple form: a charge a(x) per unit time, a charge b(x) per unit volume of traac carried, and a charge c(x) per connection, where the triple (a(x); b(x); c(x)) are xed at the time of connection acceptance as a function of the connection contract x. This form of tarii is also able to reveal user preferences concerning delay tolerant traac, and thus promises to provide a uniied pricing model over a wide range of quality of service classes.