Institute for Systems Research

Ourfirst contribution is the use of Fair Queueing in conjunction withProbabilistic Fair Drop, a new buffer management policy to allocatebandwidth and buffer space in the gateway, to ensure that all TCPflows threading the gateway achieve high end-to-end throughput andfair service.

Our second contribution is to introduce the concept ofbuffer dimensioning to alleviate the inherent bias of the TCPalgorithm towards connections with large Round Trip Time.

In supportof each of these contributions, we report on extensive simulationresults. Our scheme outperforms other resource allocation schemesreported in the literature and in particular, demonstrates significantimprovements in fairness to long RTT connections in the hybrid networkframework.

In the first part of this thesis, we analyze theimplementation feasibility and overhead of these schemes to determinewhether this overhead represents an obstacle to deployment. To this end,we employ a novel approach with real traffic traces from the Internet anda passive gateway simulator.

Having established the feasibility of suchalgorithms, we turn our attention to buffer management techniques in thepresence of fair resource allocation. Our specific focus is on developingan effective buffer management technique for satellite networks. Thelimitations of existing schemes lead us to propose a new buffer managementscheme designed with our problem space in mind.

Finally, we look at aclass of satellite enhanced gateways, termed as connectionsplitting or spoofing gateways, proposed for implementing highperformance satellite systems. The specific design issues peculiar tothis class of gateways are analyzed. A novel architecture for fair resourceallocation in spoofing gateways is then proposed. The efficacy of ourarchitecture in providing fairness and protecting adaptive flows againstmisbehaved and non-adaptive flows is demonstrated by means of simulation.