S-OSPF: A Traffic Engineering Solution for OSPF Based Best Effort Networks

Abstract

Abstract-Open Shortest Path First (OSPF) is one of the most widely used intra-domain routing protocol. It is well known that OSPF protocol does not provide flexibility in terms of packet forwarding to achieve any network optimization objective. Because of the high cost of network assets and commercial and competitive nature of Internet service provisioning, service providers are interested in performance optimization of their networks. This helps in reducing congestion hotspots and improving resource utilization across the network, which, in turn, results in an increased revenue collection. One way of achieving this is through Traffic Engineering. Currently traffic engineering is mostly done by using MPLS. But legacy networks running OSPF would need to be upgraded to MPLS. To achieve better resource utilization without upgrading OSPF network to MPLS is a challenge. In this paper we present a simple but effective algorithm, called Smart OSPF (S-OSPF) to provide traffic engineering solution in an OSPF based best effort network. We formulate an optimization problem based on the traffic demand to minimize the maximum link utilization in the network. Routing of the traffic demand is achieved using OSPF. We have simulated S-OSPF on real networks of two service providers. Simulation results show that S-OSPF based traffic engineering solution performance very closely follows the optimal solution.

Load-balanced routing with selective even traffic splitting

“…Networks 1-4 are presented in [2]. Networks 5 and 6 are presented in [4]. Networks 1-4 in Figure 1 (a)-(d) are used as typical backbone networks [2].…”

“…Networks 1-4 in Figure 1 (a)-(d) are used as typical backbone networks [2]. Networks 5 and 6 in Figure 1 (e)-(f) are presented in [4], which are the Cable and Wireless network and CRL network, respectively, available at [8].…”

“…Mishra et al presented Smart OSPF (S-OSPF) in [4] in order to improve the performance of legacy OSPFbased networks without changing link weights. In this approach only source edge nodes distribute traffic to the neighbor nodes with optimum ratios that are obtained by solving the Linear Programming (LP) problem.…”

“…In S-OSPF presented in [4], [5], each source edge node needs an additional table with optimal distribution ratios for traffic entering into the network. A classical IP forwarding table is used for the transit traffic.…”

Network-resource deployment considering both resource amount and operation-risk reductions

“…Most of have focused on flow management, such as traffic routing, or establishment of logical paths over a given physical-network resource under various types of pipe [1,2] or hose traffic models [3,4]. Their aim was to minimize the maximum link-utilization rate over given physical links or to increase robustness against traffic-demand fluctuations.…”