Proposal and evaluation of a virtual router migration policy in IP networks equipped with adaptive link rate line cards

The design of an energy efficient IP network is one of the most important challenge that researchers have begun to address in the last decades. A promising resource consolidation technique to improve the energy efficiency of Internet is based on the virtual router migration: when traffic decreases virtual routers are moved and consolidated in fewer nodes of the underlying physical network in order to turn off empty physical nodes. Unfortunately the migration of virtual routers involves reconfiguration costs depending on implementation details and characterized, for instance, by the revenue loss due to Quality of Service (QoS) degradation during the migration process. In this paper we propose a methodology for the evaluation of migration policies taking into account both the operation (in terms of energy consumption) and reconfiguration costs. The technique is applied in networks in which the line cards of the routers implements the Adaptive Link Rate (ALR) technique and whose power consumption is traffic dependent.