Minimum congestion traffic engineering with multi-resource constraint

As networks evolve to carry multi-service traffic, each flow's bandwidth requirement is getting very diverse. We notice that even though the bandwidth usage level at a certain link is not high, if the number of connections carried on the link is excessive, it should be regarded as congested. We introduce connection resource notion into the traffic engineering. By incorporating the bandwidth resource notion and connection resource notion together into the problem formulation, we set up a more precise model for the multi-service network. To represent congestion cost at the links effectively, a nonlinear convex curve is used. The curve is then piece-wise linearized in the LP problem formulation. A calculation algorithm to get the link metric from the solution of the optimization problem is devised. In our framework, the congestion cost is caused either by the shortage of bandwidth or connection resource. Under the shortest path first routing scheme, we show through numerical experiments that the link metric set calculated by the new algorithm effectively reduces the congestion cost.