Network performance improvement through evaluation of bicriteria routing methods in transport networks

Bandwidth allocation and management is of paramount importance for telcos mainly in packet transport networks where bandwidth needs an even more tricky control than in the previous circuit-based SDH networks. In these new transport networks, as is the case of MPLS-TP or Carrier Ethernet networks, it is very important to balance the traffic load distribution in order to avoid localized overloads when some parts of the networks still have available bandwidth. The load balance in the network can improve the fulfillment of the service level agreements and the network performance, namely with respect to the amount of carried traffic. In point-to-point (p2p) virtual connections it is well known that the shortest paths obtained through the hop count metric can lead to an inefficient load distribution. In order to better distribute the traffic over the network other metrics that can be used in shortest paths algorithms have been proposed in the literature. In this paper we present a bicriteria approach in which the first objective has the purpose of better distribute the traffic in the network and the second objective function intends to minimize the amount of network resources involved in each virtual connection. This is a general approach that can be applied to different kind of virtual connections such as point to multipoint (p2m) or multipoint to multipoint (m2m). This paper is focused on the algorithms and the methods involved in the calculation and path selection for p2p connections and also presents a network performance study of the addressed methods, considering realistic transport networks.