Achieving Near-Optimal Traffic Engineering Solutions for Current OSPF/IS-IS Networks

Traffic engineering is aimed at distributing traffic so as to optimize a given performance criterion. The ability to carry out such an optimal distribution depends on the routing protocol and the forwarding mechanisms in use in the network. In IP networks running the OSPF or IS-IS protocols, routing is along shortest paths, and forwarding mechanisms are constrained to distributing traffic uniformly over equal cost shortest paths. These constraints often make achieving an optimal distribution of traffic impossible. In this paper, we propose and evaluate an approach that is capable of realizing near optimal traffic distribution without any change to existing routing protocols and forwarding mechanisms. In addition, we explore the trade-off that exists between performance and the overhead associated with the additional configuration steps that our solution requires. The paper\u27s contributions are in formulating and evaluating an approach to traffic engineering for existing IP networks that achieves performance levels comparable to that offered when deploying other forwarding technologies such as MPLS