A Hybrid Admission Control Scheme for Broadband ATM Traffic
Ernst Nordström · Psychology Press eBooks · 2013
The traffic carried by an individual link are assumed to originate from independent and periodic on/off sources. An periodic on/off source alternates deterministically between burst (on) periods and silent (off) periods with constant characteristic durations. During the burst period, the source transmits packets (called "cells" in ATM terminology), at a constant characteristic cell rate. According to [8], it is widely believed, although not formally proven, that the periodic on/off source represents the "worst case" output of the traffic enforcement function (e.g. implemented by two running windows or two Leaky buckets). Hence, if the connections are represented by periodic on/off sources, the performance analysis will be conservative. The periodic on/off source is characterized by three parameters [8,9]: It is very difficult to evaluate the link performance in the deterministic case. However, it is known that more variable burst-and silent-period durations lead to larger queueing build up [8). In particular, if exponentially distributed durations are used, as in the fluid flow cased below, the performance analysis will again be conservative.