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Internet2 QoS: Overview and Early Experiences Russ Hobby December 4, 2000Campus Focused Workshop on Advanced Networks
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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How We Got Here (short version)
Began chanting: enable advanced applications, Assessed requirementsRecommended DiffServSelected Premium service to meet demands of loss/jitter sensitive appsCharted QBone initiative Specified QBone architectureNow proceeding to implement it and tweak the architecturearchitecturedeployment
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Internet2 QoS Milestones1/2Bay Workshop QoS WG DiffServ RecommendationQBone initiative launchedEvanston QIGRTP QIGQBone architecture last callLas Cruces QIGQPS demonstrated (nM demo)QConBBopQUALITQIG opened Pittsburgh QBone BOFQBone architecture draft (v1.0)QBone CFPHouston I2/DOE QBone Workshop Early Internet2 QoS requirements gatheringAPS Test Program launched QBone Forum launched
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Internet2 QoS Milestones2/2You are here!SC2K QBone demoToronto QoS BOFWG re-chartering
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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IntServ/RSVP vs DiffServIntServ/RSVPBBBBPer-flow service state at every hopAbstract/manage each clouds resources (BBs) Packets colored to indicate forwarding behaviorFocus on aggregates not individual flowsPolicing at edge to get servicesScalability problemsDiffServFocus on multipoint multicast
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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DiffServ OverviewApplications contract for specific QoS profiles Policing at network peripheryColor packets with a few simple, differentiated per-hop forwarding behaviors (PHBs) Indicated in packet headerApplied to PHB traffic aggregatesPHBs + policing rules = range of servicesDS domains contract with each other for aggregate QoS traffic profilesPolicing at cloud-cloud boundarySupports simple, bilateral business agreementsExploits edge/core distinction for scalability
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Example Service #1: PremiumAssurance: like a leased line PHB: Expedited Forwarding (RFC 2598)EF in separate queue configured with minimum departure rateExample mechanisms: strict priority, MDRR, WFQPolicing: police to a specified peak rate and drop out-of-profile packets; effectively a leaky bucket with depth 1 MTU
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Example Service #2: Controlled LoadAssurance: network looks lightly-loaded for conforming traffic PHB: Assured Forwarding (RFC 2597)4 independent AF classes3 drop preference levels within each classExample mechanisms: WRED, WFQPolicing: police to specified rate and burst profile, remarking out-of-profile packets to have higher drop probability
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Example Service #3: CoSAssurance: better than JoePHB: drop the lower classes first (AF or class selector PHBs) Policing: could be based on anything (e.g. higher priority for the CEO)A.K.A.Olympic classes of BE service (e.g. Gold, Silver, Bronze)
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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QBone ArchitectureA Service: QBone Premium ServiceBuilt on Expedited Forwarding (EF) (RFC 2598)Assurance: near-zero loss & low, bounded jitter for marked traffic conforming to a specified peak rate a.k.a. virtual leased line, virtual wireReservation Setup ProtocolNow: long-lived, manual setupProposed: SIBBS protocol between QBone domains; RSVP end-to-end between hostsQBone Measurement ArchitectureUniform collection of QoS metricsUniform dissemination interface
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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QBone E2E PictureKey
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Abilene Premium Service (APS)Goal:Make APS a reference implementation of the QBone architectureWhy?Catalyst: Enable wide-area QoS experimentation and propagate Abilenes experiences to larger communitySafety Belt: Congestion is only one success catastrophe away!The Team:UCAIDIndiana UniversityI-TECs (NCNI, OARnet)CiscoQwestNortelNLANR/NCNE
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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APS ParticipationParticipation CriteriaAbilene connector status necessary but not sufficientQBone participationCapability of access router / Abilene edge cardCurrent ParticipantsMAGPI (U. Penn)iCAIRPSC (Penn State)OARNet (Ohio State)Others in the wingsNASA EOSVarious internationalANLUIUCDOE Science GRID (peering transit network)
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Initial Engineering Plan (obsolete)Automated Setup(GTS)(Surveyor + SNMP + HTTP)(Firehose CAR)(Whiteboard + CLI)(MDRR)
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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APS Phase 1: SweetwaterFirst, crawlIngress policing Measurement feedbackLimited technical supportNo priority queuing yet, but still get benefit of Abilenes over-provisioning!GoalsBegin to establish operational practices for responding to admissions requests Provide participants with the experience of sitting behind a policer
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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APS MeasurementsGoal: implement QBone measurement architecture (collection + dissemination) for a single QBone domainHoped-for Side Effects: Tools to ease implementation for othersAdjustments to QMA based on implementation experiences
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Committed Access Rate (CAR)Classifies traffic based on certain matching criteria and meters it to a leaky bucket traffic profileDepending on metering result, different actions applied (drop, transmit, set DSCP,) Syntax:rate-limit {input | output} [access-group [rate-limit] acl-index] bps burst-normal burst-max conform-action action exceed-action action
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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CAR Experience
For the most part, CAR is exactly what the DiffServ doctor orderedHowever, there are some limitationsPerformanceToken bucket depthClassification of DiffServ aggregates
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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CAR Limitation 1: Performance On E0 edge cards, no ASIC support for CAR there is a performance hit
pps @ 256 bytes* Preliminary E0 CAR performance figures under retest by ITEC-NC
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Addressing CAR PerformanceOut of our handsThe Plan: Load on access interfaces is still light, so performance not really an issue for nowWait for E3 edge cards, which will have CAR in hardware
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Virtual Trunk vs.Firehose ClassificationThe good news: CAR can also classify by:qos-group (Cisco proprietary concept)With packets assigned to QoS groups through QoS Policy Propagation via BGP (QPPB)
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Abilene Architecture Limitation: Porous Edge ProblemQoS theft problem with current architectureMDRR (EF forwarding) on interior interfaces easily subverted by unpoliced connectors
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Current Engineering Plan (GTS)(Surveyor + SNMP + HTTP + WHOIS + traffic matrices)(CAR + QPPB + PIRC filtering?)(Whiteboard + CLI)(MDRR)
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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SC2000 Interdomain QoS DemoNovember 6-9, 2000Premium service over two wide-area pathsLBNL-ESnet-Abilene-SCinet-Internet2 boothStanford-CalREN2-Abilene-SCinet-Internet2 boothCongestion induced at multiple pointsCD-quality interactive audio application shown with/without QoSESnet and Abilene QoS capabilities formed nucleus of QBoneSC2000 Network Challenge Winner: "Most Captivating and Best Tuned Award"
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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AbileneInternet2 SC2000 Boothcore-conf Cisco 12008ESNet/DOE Science Grid10 MbpsOC-3OC-48CalREN2OC-12OC-12OC-12LBNLDevice controlGEGETraffic GeneratorsStanford UniversityI2-GW Cisco 12008OC-3OC-3* All links 100Mbps fast Ethernet (FE) unless otherwise notedInterdomain Quality of Service DemoSCinetOC-12= congestion + QoS control
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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DeploymentGood News:DiffServ functionality in most modern routersMany hosts support QoS signaling Lots of isolated testbed trialsSome partial backbone implementationsBad News:Weak demand Turnkey solutions are a long way offVendor implementations dont always live up to hypeHR scarcityBottom line:Progress can be made, but it takes a lot of people, time, and effort
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Going ForwardNeed increased focus on low-hanging fruitLess than Best-Efforts (LBE)Ad-hoc CoS at congestion pointsBasic LBE ideaLow-priority traffic classAgree on an Internet2 LBE code point BenefitsTraffic managementLicense to hog (some users are self-policing)New advanced applications (e.g. large scale distributed computation)Its easy!
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Starvation: Making LBE StrongerDefine starvation class selector (SCS)An SCS packet MUST never consume a network resource desired by a non-SCS packetCorollary 1: there must not be a configured minimum departure rate for SCS trafficCorollary 2: all queued SCS packets must be evicted before a forwarding element can drop a non-SCS packet (probably difficult to implement)Result: its the dual of EF!
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Any Questions?
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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For more information...Internet2 Home:http://www.internet2.edu/Internet2 QoS Working Group Home:http://www.internet2.edu/wg/qos/QBone Home:http://qbone.internet2.edu/Abilene Premium Service Home:http://www.internet2.edu/abilene/qos/
Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
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Internet2 QoS: Overview and ExperiencesCampus Focused Workshop on Advanced Networks (December 4, 2000)
Architecture (SIBBS)Communication (Workshop, QBone forum)Implementation (APS)OWDP coloring DSCPATM cards in NYCM and IPLS (one port on qOC3 ATM) - results will be more realistic - addresses advertized outside of Abilene - throughput source/sink; bursts up "OC3 line rate"
nycm-pc.abilene.ucaid.edu
Plan:
Washington DC (within 1 week); Deploy at all nodes with next two; could repond to priority needs if they arise
QPS quite similar to IntServ GSOC-12 POSOC-3 POSOC-12 ATMqOC-3 ATM23500072000235500588251787007200015340044675