Testing of DiffServ performance over a U.S. Navy satellite communication network

The U.S. Navy´s automated digital network system (ADNS) serves as the primary means of ship-to-shore and ship-to-ship WAN connectivity. A major limitation of current ADNS networks is their inability to provide prioritized service for mission-critical traffic and end-to-end quality of service over high-delay, low-bandwidth satellite links. Accordingly, an upgrade strategy has been developed to provision ADNS with differentiated services (DiffServ) and priority queuing. Weighted random early detection (WRED) is a key congestion avoidance mechanism within the ADNS DiffServ model. This paper describes the results of ADNS QoS testing of the proposed WRED configuration to ascertain its performance relative to best-effort networks. An alternate WRED configuration is proposed to further enhance network performance. Test results suggest that use of the alternate WRED settings will improve throughput and maintain low packet loss rates for high-priority traffic.