Analysis and modeling of ATM traffic data

This paper describes a study of ATM (asynchronous transfer mode) cell data considering both the analysis and the modeling of the data. For the data analysis portion of the work, cell counts per unit time are done, and interarrival times between cells are determined. Source modeling is done for the two large VBR (variable bit rate) users and a CBR (constant bit rate) user from the data. From the empirical distribution of interarrival times, the source modeling is made by a sequence of pairs of random variables (X, Y) where X represents the cell bursts and Y represents the interarrival times between bursts. Within each burst, the distribution of cells is determined by a finite state Markov chain, and the interarrival times of the bursts are also determined by a different finite state Markov chain for two users. For the main user, the interarrival time between bursts is dependent on the previous burst size. The model is validated by comparing the interarrival times of the model and of the trace data. The analysis of the queue in the buffer is done by computing the sample mean, variance, and maximum of the buffer usage. Quantiles of the tail of the queue are also determined, as well as mean cell delays and cell loss ratios. The model's characteristics are typically similar to the data's characteristics.