Performance of broadcast and unknown server (BUS) in ATM LAN emulation

Abstract

In this paper, we develop performance models of the Broadcast and Unknown Server (BUS) in the LANE. The traffic on the BUS is divided into two classes: the broadcast and multicast traffic, and the unicast relay flow. The broadcast and multicast traffic is assumed to form a Markov Modulated Poisson Process (MMPP). The traffic for a particular unicast relay flow is an MMPP as well. However, the number of active unicast relay flows sojourning on the BUS is determined by a tandem queueing system, where the flow arrival process is Poisson, the address resolution delay is exponentially distributed, and the connection setup delay is three-stage Erlang distributed. The size of data frames in traffic flows is a random variable with three possibile values: short, medium, and large. In order to deal with the intractability (i.e., largeness and stiffness) of the underlying Markov chain, a hierarchical model is used to decompose the system. With the help of Stochastic Petri Net Package (SPNP), a software package for the automated genaration and solution of Markovian stochastic systems, and the decomposition method, we study the performance of the BUS module under different loads. We also investigate the effect of address resolution delay and conection setup delay on the performance of the BUS.Index Terms-ATM, broadcast and unknown server, LAN emulation, stochastic petri net package (SPNP), stochastic reward nets.