A simulation study of fair queueing and policy enforcement

Abstract

This paper describes the results of research into algorithmsfor realizing improved control over the distribution of router and linkresources among the users of a packet-switched network. It reports theresults of simulation experiments designed to evaluate -- in the contextof the current Internet architecture and protocols -- the effectivenessof various router algorithms as tools for enforcing resource allocationpolicies. Two variants on the fair queueing algorithm described inDemers, Keshav and Shenker are compared (in simulation experiments) tothe familiar first-come-first-served (FCFS) discipline as mechanisms forenforcing a range of bandwidth allocation policies. The variations onfair queueing studied here present innovations designed to simplifyimplementation in typical router systems. The results reported heresuggest that a fair queueing discipline enforces both uniform andnon-uniform resource allocation policies better than does the FCFSdiscipline.