SCPS-TP, TCP and Rate-Based Protocol Evaluation For High Delay, Error Prone Links

Abstract

This paper describes testing performed to validate operation of Space Communications Protocol Suite Transport Protocol (SCPS-TP) relative to the specification and perform a comprehensive comparison of SCPS-TP protocol options to IP based protocols.Tests were performed at Glenn Research Center to validate the operation of SCPS-TP relative to the Consultative Committee on Space Data Systems (CCSDS) specification, to perform a comprehensive comparison of SCPS-TP protocol options to IP based protocols, and to determine the implementation maturity level of these protocols -particularly for higher speeds. The testing was performed over reasonably high data rates of up to 100 Mbps with delays that are indicative of near planetary environments. The tests were run for a fixed packet size, but for various errored environments. The results indicated that SCPS-TP congestion-friendly options perform slightly better than TCP SACK protocols at moderate and high error-rates. The results also show that existing standard transport protocols and capabilities (drawn from a variety of communities) appear to satisfy all known mission needs.

Promoting the use of reliable rate-based transport protocols: the Chameleon protocol

“…Indeed, previous studies (Sharafkandi and Malouch, 2005;Kawadia and Kumar, 2005) have demonstrated the poor TCP performances over wireless and multi-hop networks while other emphasize the good behaviour of rate-based congestion control over these networks (Chen et al, 2004;Anastasia and Passarella, 2003). In the context of satellite communications, several studies have also demonstrated the benefit of using ratebased congestion control protocols compared to TCP window-based variants and in particular in (Lawas-Grodek et al, 2002), the authors present performances comparison between SCPS-TP, TCP, TCP-Vegas and rate-based protocols which clearly show the strong benefit obtained by the latter in terms of throughput efficiency over long delay links.…”