Design and operation of packet-switched networks with uncertainmessage requirements

An important concern when choosing the link design and message routes is the uncertainty regarding future average hourly message requirements between sources and destinations. A model is proposed for this problem which accounts for the uncertain average number of source-destination messages by representing them as random variables. The model also allows use of the public switched telephone network (PSTN) to accommodate some of the message requirements. This is especially important with the advent of ISDN, which will offer high-speed capacity on a universal basis. Most previous research on packet-switched network design and operation has assumed known average message requirements (although actual message requirements vary according to a Poisson process) and has focused exclusively on the use of leased lines without the availability of the PSTN. These leased lines have fixed monthly costs for specific point-to-point transmission, whereas PSTN lines can access any node from a given location. It is shown how to accelerate convergence of the flow-deviation algorithm for solving the model. Computational results are reported