On stability of virtual topologies in dynamic multilayer networks

The paper addresses the problem of unwanted stabilization of a virtual topology in a dynamic multilayer network using the Packet-Packet-Lambda (PPL) routing strategy. The PPL strategy was already proposed in several papers and is perceived as a valuable solution to the multilayer traffic routing problem in a network with lightpaths created on demand. However, as it is shown, usage of the strategy may bring catastrophic results, since this strategy may create in some point of time an inefficient, extremely stable and long lasting logical topology, which results in a highly penalized network performance. Therefore, enhancements to the strategy are necessary. We show some directions for such improvements.