An Algorithm for Optimal Route Selection in SNA Networks

The problem of selecting a single route for each class of service and each pair of communicating nodes in an SNA network is considered. The nodes, links, sets of candidate routes, and traffic characteristics are given. The goal is to select a set of routes which minimizes the expected network end-to-end queueing and transmission delay. Queueing is modeled as a network ofM/M/1queues which leads to a nonlinear combinatorial optimization problem. Using Lagrangean relaxation and subgradient optimization techniques, we obtain a tight lower bound on the minimal expected delay as well as sets of feasible solutions for the problem. An experimental interactive system has been used to evaluate the procedure; very favorable results have been obtained on a variety of networks.