Joint resource conserving and load distributing approaches for routing of survivable connections

This paper investigates the problem of on-line routing of bandwidth guaranteed paths with end-to-end restoration. We first present the characteristic of bandwidth sharing on backup paths for varying degrees of network state information. We also propose a new Partial Information Scenario (PIS) in which the propagated state information is judiciously selected, such that the protocol overhead remains identical to that of the original PIS. Then, an iterative variant of two-step routing approach is used to compute link–disjoint active and backup paths. In order to implement this restorable routing, we consider a new class of weight function as the choice of cost metric.Generally, there are two schools of thought regarding the choice of link cost: resource conserving and load distributing. This paper suggests the use of both approaches for calculating active and backup link costs, to simultaneously achieve an economical usage of resources and efficient distribution of traffic load on the network. Comparing with the existing best-known algorithms, we show that our method outperforms the others with respect to the number of rejected requests as well as the total bandwidth consumption. Moreover, it has a much shorter running time, which makes it more attractive for on-line routing.