Departure process characterization of the leaky bucket with modified geometric mode

An ATM network is expected to support a large number of bursty traffic sources, and therefore, it is critical to control the network traffic in order to provide a desirable level of performance. The "leaky bucket" scheme is a typical policing or usage parameter control (UPC) mechanism in ATM networks. We build a modified geometric model (MGeo) for the interdeparture time distribution of the leaky bucket. The control effects of leaky bucket are extensively examined, from the viewpoint of smoothing out the burstiness of the input traffic, with numerical examples. The smoothing effect is reflected by the squared coefficient of variation (SCV) of the interdeparture time of the departure process from the leaky bucket. We offer a procedure to fit the interdeparture time distribution of the leaky bucket to the MGeo model. We also provide simulation results to verify the model. The trade-off between the burstiness of the departure process and the cell delay is examined.