Evaluating TCP/IP performance over satellite networks

Thompson, Richard (2004-04)

Thesis (MScEng) -- Stellenbosch University, 2004.

Thesis

ENGLISH ABSTRACT: Interest in TCP/IP as a communication protocol for use in space communication has increased substantially with the growth of the world wide web (WWW). TCP/IP is a relevant communication protocol for space based communication systems that need to access the broader terrestrial communication network. Low Earth Orbit(LEO) satellites have very short delay times between themselves and the ground, and correspondingly very short connection times. Staying in contact with a LEO satellite continuously through a space-based network requires large constellations of satellites and complex routing strategies. Connectivity with the world wide web using a widely accepted protocol such as TCP/IP is desirable because it would make communication with the satellite over a terrestrial station possible, were it to route communication onto the WWW. This thesis looks at the expected TCP/IP performance over satellite network links, identifies problem areas for current TCP/IP technologies, and makes suggestions for optimizing TCP/IP over such links. The thesis also introduces a new performance benchmark, the equivalence level, allowing for the simplified description of TCP throughput behaviour over a broad range of network parameters. The performance of the Linux kernel release 2.4.18 TCP/IP stack is also evaluated.

AFRIKAANSE OPSOMMING: Die belangstelling in TCP/IP as ’n kommunikasie protokol vir gebruik in die ruimte het kenmerklik toegeneem met die groei van die wereld wye web (WWW). TCP/IP is ’n relevante protokol vir kommunikasie stelsels in die ruimte, veral met die doel om toegang tot land gebaseerde kommunikasie netwerke te kry. Lae wentelbaan sateliete het baie kort vertragingstye tussen die aarde en die sateliet, en gevolglik baie kort verbindingstye. Groot sateliet konstelasies en komplekse verbintenis strategie word benodig om ’n lae wentelbaan sateliet deurentyd in kontak te hou met ’n ruimtegebaseerde netwerk. Verbinding met die wereld wye web deur die gebruik van ’n wyd aanvaarde protokol, soos TCP/IP, is wenslik, want dit sal kommunikasie met die sateliet oor ’n aardgebaseerde stasie moontlik maak, sou dit kommunikasie oor die wereld wye web stuur. Hierdie tesis kyk na die verwagte werking van TCP/IP oor sateliet netwerk konneksies, identifiseer probleme met huidiglike TCP/IP tegnologie, en maak voorstellings vir die optimale funtionering van TCP/IP oor sulke konneksies. Hierdie tesis stel ook ’n nuwe werkverrigtings maatstaf, die gelykheidsvlak, wat die vereenvoudige beskrywing van TCP/IP data tempo gedrag oor ’n groot variasie van netwerk parameters toelaat. Die werking van die Linux Kernel 2.4.18 TCP/IP stapel word ook geevalueer.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/49954
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