QoS-based routing algorithms for ATM networks

Cell loss probability (clp) is one of the most important measures of quality of service in an ATM network. In this paper we present two routing algorithms for ATM networks that meet the clp requirements of bursty ON-OFF sources that request connection while ensuring that the clp requirements of the existing calls are not compromised. The rst algorithm checks the entire set of feasible routes while the second algorithm remembers the last successful route for each OD pair and is consequently simpler to implement. Our numerical results show that the clp requirements are achieved while maintaining low call blocking probabilities. Further, the routing algorithms are sensitive to the clp requirements and respond to small changes in them. If the clp requirements are made stricter, then the routing algorithms continue to maintain these new requirements at the expense of small increases in the call blocking probabilities. Di erent cell loss probability criteria can be accommodated for di erent types of calls which may di er in parameters such as burstiness, average burst length and average or peak rates. A comparison of the two algorithms in terms of the trade-o between clp and call blocking probability is also provided which con rms the e ectiveness of the simpler second algorithm. We also present a feedforward neural network which is easily trained and which can be used for the real time implementation of the algorithms.