COMPARATIVE PERFORMANCE OF QUEUING STRATEGIES FOR LAN-WAN ROUTERS IN PACKET DATA-NETWORKS

We provide a comparative performance evaluation of packet queuing and link admission strategies for low speed wide area network links (e.g., 9600 bps, 64 Kbps) that interconnect relatively high speed, connectionless local area networks (10 Mbps). We are concerned with the problem of providing differential quality of service to inter-LAN remote terminal and file transfer sessions, and throughput fairness between inter-LAN file transfer sessions. We use analytical and simulation models to study a variety of strategies. For very low speed WAN links (e.g., 9600 bps), we demonstrate the superiority of connection oriented interconnection of connectionless LANs, with segregation of traffic streams into different connections. For 64 Kbps WAN links, there is a drop in file transfer throughputs, owing to connection overheads, but the other advantages are retained. We also provide supporting results from an experimental test-bed.