Copyright 2006 by Rules |
Internet Protocol- Quality of Service PageThis page reports the efforts made by ITTC in IP QoS research.QoS provisioning in the internet using IP has been a topic of active researchin the last few years. The efforts pursued by ITTC in this area includea study of the various approaches suggested for QoS in IP based networks,implementation of some of these approaches and evaluations of the implementations.StudyTopicsVarious approaches have been suggested for provisioning QoS in IP networks. A study of these approaches in done is this report. This report contains a number of links to related work on IP QoS.Another reporton the various approaches, with a comparison between integrated servicesand differentiated services, is donehere.Linuxhas support for QoS. A detailed study of Linux QoS Support was done. Thanksto Alexey Kuznetsov, a Linux-QoS-HOWTO(.ps)(.pdf) (HTML)was prepared. This HOWTO describes in brief, the methods to set up variouskinds of queues. The queues supported currently include Class Based Queues(CBQ), Token Bucket Flows (TBFs), priority queues, Random Early Drop (RED),DSMARK etc. Examples have been included in the HOWTO. Also wehave prepared a short HOWTO (.ps )(.pdf) (HTML.) giving an overview of netlink sockets both from the implementation and usage point of view. If you need a quick overview of the QoS support in Linux, take a lookat this presentation.This has be updated to include the new diffserv support in Linux. Implementationsand EvaluationsITTC has beenworking on a number of differentiated services related projects recently.If you need a quick overview of the work that has been done in ITTC inthe area of IP QoS, click here for a presentation that was made recently.LinuxDiffServ TestbedWe are tryingto set up a linux diffserv testbed with a Bandwidth Broker component. Thistestbed would essentially have the capabilities that are expected in afully capable diff-serv domain. Hereis a link to the presentation that was made on this recently.DifferentiatedServices in Zebra Zebra was modified to have differentiated services configuration capability.An interface to configure assured forwarding services on a linux box runningzebra was provided. Suport for expedited forwarding is under way. Send a mail to the projectgroup.DiffSpecThe designand implementation of DiffSpec, a differentiated services tool that canbe used by the administrator to configure diff-serv parameters in a linuxrouter.BandwidthBrokerA preliminaryBB has been implemented here in ITTC. The BB concept, introducedby Van Jacobson, deals the resource management in a diff-serv internet.This group deals with intra-domain interactions between the BB, hosts andthe routers in a diff-serv domain. Send a mail to thisprojectroup.SocketAPI for QoS configurationAn API wasdeveloped to use the QoS support in Linux. The current QoS support doesnot have an API, that is, there is no way to associate a socket with aqueuing discipline. Also, there is no possible means to create the queuesfrom an application program. Send a mail to theprojectgroup.PerformanceMeasurementsA diff servtestbed was set up using the linux QoS support. Assured Forwarding (AF)and Expedited Forwarding (EF) PHBs were tested. The details of thetests and the results can be obtained by following these links.AssuredForwarding testbed and ResultsExpeditedForwarding testbed and Results Linux Diff-Serv PatchesThe ds-2patch.gz patch adds the diff serv functionality to the linuxkernel. Thanks to Werner Almesberger.The iproute2.tar.gzpackage with the diffserv capabilities will help to set up differentiatedservices in Linux.Somevery interesting papersLinkSharing and Resource Management Models for Packet Networks. Sally Floyd and Van Jacobson.ATwo-bit Differentiated Services Architecture for the Internet K Nichols, V. Jacobson & L.ZhangDifferentialServices for internet and ATM Rüdiger GeibSomeuseful talksVan Jacobson'stalk on Movingthe Internet Beyond Best Effort , he discusses BandwidthBrokers in this. He has also given a talkon differentiated services.Lixia Zhang'stalk on ResourceManagement and differentiated services.ProffessorTorsten Braun's presentation on presentation on diff-serv.DifferentiatedServices LinksWernerAlmesberger's Linux diff-serv pageTheOfficial IETF page on diff-servPlease send comments and questions to the webmaster .| --BEGIN VALIDATION CODE-- Z iGcFa Qx I eRbP eMs BySbR p KbK tKmC hE kTuAnJeWhU aV qOiMlM fA iKxGn DgXnTlUcKl SeEaKvLtBqEuZgJyLjK eOcViHeQsFkL uXpRiCzWb RnO sOpTxCdKoWmGzIoHjEwJ dQ kBgPjUxNlYtFhT vCnCgW fOf FzTrUnBgW kHmStXxQ jA bI o YiQhI tC qKs FcHg ZnMxTfUuBfApQnAxZsDmZ vH wIqChXbY tDcS sYjLvWaY gE oMxOkQ j hohositeX2006 --END VALIDATION CODE-- |
