Abstract

Broadband satellite constellation networks will be required to carry all types of IP traffic, real time interactive traffic as well as non-real time traffic, warranting the need for appropriate QoS for these different traffic flows. In this paper we investigate the need for MPLS traffic engineering in GEO/MEO/LEO satellite networks to address QoS issues. We compare the service received by TCP and UDP flows when they share a link and when they are routed on explicit MPLS traffic trunks. Since MPLS traffic trunks allow non-shortest path links also to be used, the total network throughput goes up with proper traffic engineering. If UDP and TCP flows are mixed in a trunk, TCP flows receive reduced service as the UDP flows increase their rates. Also, we found that with MPLS traffic engineering we can protect real time traffic and VoIP traffic from packet loss and excessive jitter by separating them from other congestion unresponsive flows Peer Reviewed

Abstract

In this paper, we compare two routing scenarios for grooming-capable optical-beared two-layer networks that are capable of meeting the Traffic Engineering (TE) objectives. The first one applies completely dynamic WDM layer that adapts instantly to all traffic changes. The second one is based on fixed WDM topology (“lower layer”). To achieve the best performance, the fixed lightpath system is optimized in advance according to the characteristics of the expected traffic. In both cases, the upper layer is assumed to be dynamic. We perform extensive simulations to compare these two multi-layer Routing and Traffic Engineering approaches that are currently both of particular practical interest with their inherent advantages and drawbacks.