Optimizing Interconnections of Local Area Networks: An Approach Using Simulated Annealing

Abstract

The problem of selecting minimum cost topologies for the interconnection of Local Area Networks (LANs) with transparent bridges is addressed. A graph theoretic model for a LAN internetwork is developed and an algorithm for calculating internetwork flows is presented. The flow algorithm accounts for O-D flows due to hosts and overhead flows due to the bridge learning algorithm. Internetwork delays are examined and standard queueing models are used to approximate the delay of a packet traversing multiple LANs and bridges. A mathematical program minimizing system cost subject to internetwork flow constraints and delay constraints is formulated. The resulting optimization problem is a complex nonlinear integer program; it is solved using a simulated annealing heuristic algorithm. Numerical experiments have showed the heuristic to be within 0.8% of the optimum for small problems. For large problems the annealing algorithm is evaluated using a statistical technique and results indicate excellent performance. INFORMS Journal on Computing, ISSN 1091-9856, was published as ORSA Journal on Computing from 1989 to 1995 under ISSN 0899-1499.