Alternate link routing for traffic engineering in packet-oriented ISL networks

Abstract

The implementation of a satellite communication network consisting of intersatellite links provides a highly interconnected backbone in the space segment, increasing the network flexibility and reliability, while, on the other hand, introducing numerous issues related to network dimensioning, efficient resource management, adaptive routing, etc. In this paper we study two forwarding policies based on alternate link routing (ALR) and compare their performance with that of a simple forwarding policy employing shortest path routing (SPR) without options. All forwarding policies compared in this study are operating on routing tables calculated with the Dijkstra shortest path algorithm, capable of adapting to traffic load and propagation delay on the links through the appropriately selected link cost metric. Using an ISL network simulator, we demonstrate that both ALR forwarding policies can efficiently handle traffic load sharing among alternative routes, significantly reducing peak values of link load which is a central goal of ISL network dimensioning.