Buuer Management and Rate Guarantees for Tcppip over Satellite-atm Networks

In this paper we present tehniques to to improve the performance TCP/IP over satelliteATM networks, and to provide minimum rate guarantees to VCs carrying TCP/IP tra c. Many future systems are proposing to use ATM or ATM like technology to transport TCP/IP based data. These systems must be designed to support best e ort services, as well as enhanced services that provide minimum rate guarantees to TCP/IP tra c. In this paper we study four main issues. First, we discuss tehniques for optimizing TCP performance over satellite networks using the Unspeci ed Bit Rate (UBR) service. We then demonstrate that high priority background tra c can degrade TCP performance over UBR, and we discuss the use of rate guarantees to improve performance. We design a full factorial experiment to assess the bu er requirements for TCP over satellite-ATM networks. Finally, we discuss the use of the Guaranteed Frame Rate (GFR) service category to provide minimum rate guarantees to VCs carrying TCP/IP tra c. We propose the Di erential Fair Bu er Allocation (DFBA) scheme for bu er management that provides GFR guarantees to TCP/IP tra c over satellite latencies. We use full factorial experimental design with various latencies, bu er sizes, and TCP types for our simulations.