Efficient techniques and tools for intra-domain traffic engineering

Abstract

Intra‐domain routing protocols are based on Shortest Path First (SPF) routing, where shortest paths are calculated between each pair of nodes (routers) using pre‐assigned link weights, also referred to as link metric. These link weights can be modified by network administrators in accordance with the routing policies of the network operator. The operator's objective is usually to minimize traffic congestion or minimize total routing costs subject to the traffic demands and the protocol constraints. However, determining a link weight combination that meets a network operator's objectives is a difficult task. In this paper, we study the link weight optimization problem in intra‐domain networks. This problem is proved to be NP‐hard with hard protocol constraints, e.g., a flow is evenly distributed along the shortest paths between its origin and destination nodes. We present two fast heuristic approaches to generate efficient link metrics for intra‐domain routing. Some promising experimental results are reported.

Oblivious OSPF routing with weight optimization under polyhedral demand uncertainty

“…This heuristic is input several TM s and minimizes the sum of the routing costs of a given routing over all matrices. Recently, an open source version of this tabu search approach, called IGP‐WO, handling multiple demand matrices, was implemented in the TOTEM open source toolbox [25, 26]. We use the IGP‐WO implementation in our heuristic.…”

“…Consequently, Fortz and Thorup [22, 24] launch the idea of managing link weights so as to make an efficient use of network resources and improve performance. Since then, determining the link metric and hence the routing paths so as to optimize some design criteria like link‐utilization or routing cost has been the focus of the most recent research on OSPF routing [2, 25, 29, 30, 32, 38].…”

Applications of meta-heuristics to traffic engineering in IP networks

“…The main advantage of this approach is that dual variables used in the pricing problem are natural candidates as link weights. Fortz and Ümit (2007) managed to significantly improve the results obtained by the heuristic by warm‐starting the local search with the best solution obtained with dual variables of the multi‐commodity flow relaxation of the problem.…”

Online OSPF weights optimization in IP networks

“…Although they are usually set to one, the weights of the links, and thereby the shortest path routes, can be changed by the network operator. Given a set of traffic demands between origin/destination (OD) pairs, the link weight optimization problem amounts to finding a set of link weights that optimize a given perfor- mance measure, e.g., the maximum utilization rate of the links (see [3,4,5,6] and references therein). An illustrative example is given in Figure 1.…”