EVALUATING FLEXIBLE ROUTING FOR AN INTERTOLL TELEPHONE NETWORK.

The potential advantages of flexible routing are examined for a realistic intertoll telephone network. Cost savings exclusive of implementation costs are evaluated by dimensioning this network for sixteen hours of traffic under flexible routing and hierarchical routing. To dimension a network for flexible routing, it is assumed that trunks can be re-routed hourly. A linear program dimensions a network satisfying trunk requirements at all hours, and determines trunk routing at each hour. Cost savings of 8% from flexible routing over hierarchic routing are found. A practical implementation of flexible routing could operate somewhat differently, and net savings would be reduced by implementation costs. Even if these savings are small, an important advantage of flexible routing in an intertoll network is greater tolerance to equipment failures and traffic fluctuations.