A conceptual framework for multiple-criteria routing in QoS IP networks

The provision of quality of service (QoS) in IP-based networks, namely QoS IP networks, has led to new demands for routing methods, protocols and algorithms. It is widely recognized that such QoS routing should take into account multiple criteria. In this case, contemporary approaches in multiple-criteria analysis should be taken into account, and they differ essentially from classical routing approaches. An alternative to classical routing algorithms that are not quite able to respond to all the challenges of QoS IP networks, especially from the perspective of Future Internet, is to change routing approaches and algorithms to provide for consistent multiple-criteria routing approaches. This is also related to the understanding of the concept of hierarchy in routing, discussed in the paper. The paper recalls the concept of objective ranking, shows its appropriateness for consistent multiple-criteria routing and presents a conceptual framework for routing based on objective ranking, including hierarchy of routing optimization and multiple routing tables. The paper has a conceptual nature, with the purpose of analyzing possible approaches to multiple-criteria routing that might be useful if not today, then in the engineering of future networks. However, a network engineering interpretation of the concepts proposed here is also presented.