Key Benefits for Maximizing VoIP Performance

• Wire-speedswitchingandroutingperformance

• Non-blockingarchitecture

• Lowlatency

• Lowjitter

Key Benefits for Maximizing VoIP Resiliency

• ExtremeXOS®-aconsistentoperatingsystemacrossallswitchingplatforms

• EthernetAutomaticProtectionSwitching(EAPS)protocolforcarrierclassLayer2resiliency

• ExtensibilitywithWidgetscriptingandtightintegrationofexternalapplicationsviaExtremeXOSInSite(XMLSDK)

Voice-over-IP (VoIP) Solution Overview

Businesseshavetraditionallymaintainedseparatevoiceanddatanetworks.Akeyreasonforthisisthatlegacynetworktechnologiescouldnotmeettheperformancerequirementsandvoicequalityneededtosupportreal-time,delay-sensitivevoicetraffic.Recentadvancesinnetworkingtechnology,suchastrafficprioritizationandbandwidthmanagementtools,havemadeitpossibletobuildeffectiveconvergedvoiceanddatanetworks.

Convergednetworksreducecostsbyeliminatingredundanthardware,communicationsfacilities,long-distancechargesandsupportstaffs,allwhileenablinganewgenerationofintegratedvoiceanddataapplications.Asaresult,convergednetworksreducenetworkcomplexityandimproveintegrationofdisparatebusinesssystems.

BypacketizingvoicetrafficintoIPpacketsfortransmissionoverdatanetworks,Voice-over-IP(VoIP)isbecomingakeytechnologyconsiderationformanysmallercompaniessearchingtolowercoststhroughtollbypassandlargerenterpriseslookingtotakeadvantageofconvergedvoiceanddataapplications.Withacomprehensivesuiteoftoolstomanageandensureintegrityofvoicetraffic,ExtremeNetworks®providesthemosteffectivenetworkinfrastructureforsupportingVoIPandotherconvergedapplications.Toensureabest-of-classVoIPsolution,ExtremeNetworkspartnerswithstrategicVoIPtechnologypartners.

BydeployingVoIP,companiescanoffloadinternalcorporatetelephonytrafficfromthePrivateSwitchedTelephoneNetwork(PSTN)ontothedatanetwork.VoIPcanalsobeusedtosupporte-commerceapplications(suchascallcenters),wherecriticalcustomeraccountinformationisbroughtuponthecomputerscreenduringcustomerservicephonecallsbysimplypunchinginacodeorpassword.

Deploying VoIP in the LAN and the WAN IPtelephonyintheLANrequiresseveralthingsfromthenetworkinfrastructure.Thetoptworequirementsarepredictableperformanceandaresilientnetworkdesign.WhileVoIPisnotabandwidth-intensiveapplication,itdoesrequirethatbandwidthalwaysbeavailable,voicetrafficbeidentifiedashighpriority,andthatQualityofService(QoS)bemaintainedbyminimizinglatency(delay)andjitter(delayvariation).

TelephoneusershaveveryhighexpectationsbecausetheyareaccustomedtotheQoSprovidedbythePublicSwitchedTelephoneNetwork(PSTN)andlegacyPrivateBranchExchange(PBX)basednetworks.Theseconnection-oriented,circuit-switchednetworksprovideeachuserwithdedicatedbandwidthforthedurationofeachcall.Theresultisextremelylowlatencyandjitter,andminimaldisruptiondueto“noise”ontheconnections,allowinguserstocarryonnaturalconversations.

© 2009 Extreme Networks, Inc. All rights reserved.

Extreme Networks Voice-over-IP (VoIP) Solution Overview

Extreme Networks Voice-over-IP (VoIP) Solution Overview

© 2009 Extreme Networks, Inc. All rights reserved. Extreme Networks Voice-over-IP (VoIP) Solution Overview—Page 2

bandwidthsfordifferenttypesoftraffic.Policiesaresetsofhigh-levelrulesthatdeterminehownetworkresourcesareallocatedtoapplications.BycreatingQoSpoliciesthatidentifytrafficgroupsanddefineQoSprofilesthatspecifythelevelofservicethatthosetrafficgroupsreceive,companiesutilizingPolicy-basedQoSareassuredthatintegrityofmission-criticalVoIPtrafficinrealtime,evenduringperiodsofnetworkcongestion.

AvailableonallExtremeNetworksswitches,rateshapingandDiffServareothertrafficmanagementandbandwidthprioritizationtoolsthatcanbeusedtosupportVoIPtraffic.BandwidthmanagementisperformedonthebasisofDiffServ(formerlyknownasIPTOS)codepoints.Witheighthardwarequeuesperport,theminimumandmaximumbandwidthparametersofeachqueuecanbemappedtoDiffServcodepointstoprovidetrafficprioritizationandrateshapingfordifferentclassesoftraffic.

Figure 1: Voice-over-IP (VoIP) in Action

Building the Right Infrastructure to Support VoIPOneofthekeychallengesinimplementingVoIPistodesignandbuildanIPbasednetworkthatmeetsstringentQoSrequirementsandiscomparableinperformancetoconventionalcircuit-switchedtelephonenetworks.Highlatencyforwardingandbest-effortdeliveryprovidedbytraditionalswitchesarenotacceptablefordelay-sensitivetrafficlikeVoIPbecauseitdoesnotprovidelatencyorbandwidthguarantees.FromtheperspectiveofanIP-basedEthernetnetwork,aVoIPpacketcontainingpartofatelephoneconversationisnodifferentthanadatapacketcontainingpartofanemail.Fromtheperspectiveoftheendpoints,differenttypesoftraffichavedisparatedeliveryrequirements.

Forexample,emailtrafficistypicallyhandledusingthestore-and-forwardprocess.Itdoesnothavetohappeninrealtime.Anemailtransmissiondoesnothavetobestreamedfromoneendpointtoanotherendpointtobesuccessful.Conversely,VoIPtrafficdemandsreal-timededicatedbandwidthforanallottedtime.TocompleteasuccessfulVoIPsession,thenetworkmustbeabletoclassifyandmarkvoicetrafficashighpriority,guaranteebandwidthandsupportuninterruptedstreamingVoIPpacketsbetweentwoendpointsforthedurationofthephoneconversation.

TosupportVoIPtrafficconsistentlyandreliably,anetworkmustbeabletoprovidefourthings:highperformance,lowlatencyandlowjitter,protectionandQoS.Thesefourthingshelpensurethatvoicepacketsaresentthroughthenetworkinrealtime.

Preserving VoIP Traffic with Advanced Traffic Management and Bandwidth Prioritization Tools IdealforsupportingVoIPtrafficbyminimizinglatencyandjitter,ExtremeNetworksswitchesofferPolicy-basedQoS–anadvancedtrafficmanagementtoolwhichprovidesbidirectionalminimumandmaximum

Packets In Packets Out

1 6 4

1 6 43 5 2

6 1 Increasing Priority Packets QpX - Essential Traffic

Qp1 - Best Effort Traffic

Higher Priority

Lower Priority

Classification

6 5 4

3 2 1

Figure 2: Policy-Based QoS in Action

Maximizing VoIP Performance AnExtremeNetworksapplicationsinfrastructureleveragespowerfulswitchingandQoScapabilitiesthatareinherentinBlackDiamond®andSummit®switches:

• Wire-speedswitchingandroutingperformance–Wire-speedswitchingatLayer2andLayer3ensuresthatthepacketforwardingspeed,whetheritisforadatapacketcontainingpartofanemailoraVoIPpacketcontainingpartofatelephoneconversation,willminimizeobstaclestodeployingVoIPontheLAN.

Extreme Networks Voice-over-IP (VoIP) Solution Overview

© 2009 Extreme Networks, Inc. All rights reserved. Extreme Networks Voice-over-IP (VoIP) Solution Overview—Page 3

Figure 2: Medium Enterprise Data Center

• Non-blockingarchitecture–EveryExtremeNetworksswitchhasanon-blockingswitchfabric,whichenableswire-speedswitchingandroutingperformancewithoutbeingasourceofcongestionorpacketlossforVoIPtraffic.

• Lowlatency–Aby-productofwire-speedswitchingislowtrafficforwardinglatency.ExtremeNetworksswitchesonlyintroduce8-12microseconds(msec)oflatency,ordelay,whenforwardinga64-byteEthernetpacketatLayer2orLayer3.Thisislessthanthe150-300milliseconds(ms)ofdelaythatVoIPpacketscantolerate.Consequently,thepacket-forwardingdelayincurredbyExtremeNetworkswitchesisover1,000timeslessthanthemaximumdelayVoIPtrafficwilltolerate.

• Lowjitter–Jitterisameasureofthevariationinlatencyovertime.Inanidealsituationwithnojitter,everypacketarrivesatitsdestinationwiththeexactsameamountoflatencyoveraninfiniteperiodoftime.Therealitywithallnetworksisthatsomeamountofjitterwillexist.Thechallengeistominimizethatjitter.ExtremeNetworksswitchesexhibitanaveragejitterof10microseconds(msec).Jitteroflessthan1millisecond(ms)isoptimalforVoIPtraffic.Therefore,theExtremeNetworksjitterrateisathousandtimescloserto0thanwhatisrequiredforasuccessfulVoIPsession.

Maximizing VoIP Resiliency PerformanceisjustonecriticalcomponentofasuccessfulVoIPimplementation.Anothermajorcomponenttoconsiderisbuildingahighlyresilientinfrastructureformaximumuptimeandsustainingfailureswhilekeepingthevoiceenvironmentinproduction.

ExtremeNetworksproductsprovideagilenetworkinfrastructuresolutionstokeepaheadofthegrowingbandwidthandresiliencydemandsintoday’salways-onenvironments.ThroughoutallExtremeNetworksdesignsthesethreekeyfeaturesprovideahighlyresilientinfrastructure:

• ExtremeXOS-aconsistentoperatingsystemacrossallswitchingplatforms

• EthernetAutomaticProtectionSwitching(EAPS)protocolforcarrierclassLayer2resiliency

• ExtensibilitywithWidgetscriptingandtightintegrationofexternalapplicationsviaExtremeXOSInSite(XMLSDK)

ExtremeXOSExtremeNetworksmodularedgetocoreoperatingsystem,ExtremeXOS,raisesthebarforavailabilityto

supportmission-criticalvoiceapplications.Ahighlyavailablenetworkcanalsoloweroperationalcostsbydrasticallyreducingemergencymaintenance.

TheExtremeXOSoperatingsystemhasarichsetofLayer2andLayer3controlprotocols,providesflexibilityinthedesignofhighlyresilientnetworksandhasbeendesignedfromthegrounduptosupportthenext-generationInternetProtocol,IPv6.EvenwhennotplanningtouseIPv6,ExtremeXOScanhelpsecurethenetworkusingIPv6AccessControlLists(ACLs)andhelpprovideinvestmentprotectionforthenetwork.SecuritycapabilitiesprovidenetworkcontrolandmanagementplaneprotectionviaCLEAR-FlowwhenpairedwithSentriant®NG300,ExtremeNetworksbehavior-basedthreatdetectionsolution.ExtremeXOSdramaticallyincreasesnetworkavailabilityusingprocessmonitoringandrestart.EachindependentOSprocessismonitoredinrealtime.Ifaprocessbecomesunresponsiveorstopsrunning,itmaybepossibletoautomaticallyrestart,ortakeotherautomaticcorrectiveactions,suchashitlessfailovertoaredundantmanagementmoduleorstandbystackmaster.

Ethernet Automatic Protection Switching (EAPS)Theconvergednetworkinfrastructureisrequiredtoofferscalableandagileresponsestotheever-growingdemandsofincreasingreal-timeapplications.Theunderlyingswitchinginfrastructuremusthavetheintelligenceandagilitytoaddressresiliencyissues,butdosowithsimpleandefficientsolutions.

ExtremeNetworksmeetsthisrequirementwithitsinnovativeEthernetAutomaticProtectionSwitching(EAPS)solution.Leveragingadesignfromcarrier-classresiliencysolutions,EAPSresilientring-basedtopologyisextensivelydeployedinenterprisenetworksandiswellsuitedtomeetthedemandsofconvergednetworks.

EAPSwasdesignedtoovercomethebroadcastloopproblemofEthernetnetworksandtoprovidefastrecoveryfromnetworklinkfailures.TheInternetEngineeringTaskForce(IETF)laterstandardizedtheEAPSprotocolinRFC3619.Instandardnetworkarchitectures,linkfailuresrecoverinfewerthan50millisecondswhichisequivalenttotheperformanceofSONETandSDHrecoverysolutions.ThistypeofresiliencyiscriticalfordatacentersandmissioncriticalVoIPapplications.EAPSenablesoperationalagilitybysimplifyingnetworkrecoveryinaconverged,virtualizedscalablenetwork.

Extreme Networks Voice-over-IP (VoIP) Solution Overview

© 2009 Extreme Networks, Inc. All rights reserved. Extreme Networks, the Extreme Networks Logo, BlackDiamond, EPICenter, ExtremeXOS, Sentriant and Summit are either registered trademarks or trademarks of Extreme Networks, Inc. in the United States and/or other countries. Specifications are subject to change without notice. 1294_02 5/09

www.extremenetworks.com

Corporateand North AmericaExtreme Networks, Inc.3585 Monroe Street Santa Clara, CA 95051 USAPhone +1 408 579 2800

Europe, Middle East, Africaand South AmericaPhone +31 30 800 5100

Asia PacificPhone +852 2517 1123

JapanPhone +81 3 5842 4011

Benefits of EAPS

• Sub-50msRecoveryTimeforLinkorNodeFailures:Whenalinkfailureorswitchfailureoccursincommonnetworkarchitectures,EAPSrecoverswithin50milliseconds,arecoverytimecomparabletoSONETandSDH.

• ScalableNetworkSegmentationandFaultIsolation:EAPSDomainscanprotectgroupsofmultipleVLANsallowingscalablegrowthandbroadcastloopprotection.EAPSDomainsprovidelogicalandphysicalsegmentation,whichmeansfailuresinoneEAPSringwillnotimpactotherEAPSringsandVLANs.

• ResilientFoundationforNon-StopIPRoutingServices:EAPSprovidesaresilientfoundationforupper-levelroutingprotocolssuchasOpenShortestPathFirst(OSPF)andBorderGatewayProtocol(BGP),minimizingroute-flappinganddroppedneighborswithintheroutedIPnetwork.

• PredictableRecoveryTimesRegardlessofFailureLocation:EAPSprovidesconsistentandpredictablerecoverybehaviorregardlessofwherelinkfailuresoccur.Thesimpleblockingarchitec-tureandpredictableperformanceofEAPSallowforenforceableServiceLevelAgreements(SLAs).Thisaffordseasiernetworktroubleshootingandfailurescenarioanalysiswithoutlengthytestingordebuggingondatacenternetworks.

ExtensibilityExtremeNetworksoffersanExtensibleEcosystemconsistingofDevice,Network,andHumanExtensibility.DeviceExtensibility:SwitchControlthroughExtremeXOS

Networkadministratorscansimplifymanagementprocesseswithautomationwidgets.WidgetsarescriptswhichhelpsimplifyandautomateITtasks.Theyconsistoftwosimilartechnologies;CLIScripting(StaticScripts)andUniversalPort(DynamicScripting.)CLIorStaticScriptingallowsyoutoautomateandreplicateanysetofcommandsthatareavailabletotheadministratorfromthecommandlineinterface.Thisfeatureenablesconsistentconfigurationmanagementordeploymentofnewequipmentwithoutthedangerofconfigurationerrors.Additionallogiccontrolandanalysisismade

availablethroughtheuseoftheTclscriptingfacilities.UniversalPort(DynamicScripting)advancestheconceptofstaticscriptingthroughtriggerbasedbehaviorwhichenablesthenetworkstoactonbehalfofyourITstaffwhenseveraltypesofeventsarerecognized.Advancedcontrolandanalysisforbuildingnetwork-awareapplicationsareprovidedwithExtremeXOSInSiteXMLSoftwareDevelopmentKit(SDK)at:http://www.extremenetworks.com/solutions/Insite.aspx.ThisXMLinfrastructureembracestheconceptofopenyetsecurecommunicationstoallowbusinessapplica-tionstoeasilyinteractwiththenetworkforsecuritypolicyenforcement,regulatorycomplianceandperfor-mancemanagement,andhighersecurity.Theconfigu-rationandmonitoringcapabilitiesprovidedbytheAPIsletyoucreateServiceOrientedArchitecturesolutionsthatbridgethegapbetweenapplicationandbusinesslogicwithnetworkconfigurationandevents.TheXMLSDKcanenableapplicationstocontroltheinfrastructurewithapplicationssuchas:integrationwithSalesForce.comtoautomateaserviceprovisioningtemplatefordatabaseaccesstoanewcustomerorallowingaserverloadbalancertodetermineasetofservers(allhousedonacommonswitch)arenotneededandputtingtheswitchinlowpowermode.NetworkExtensibility:NetworkControlthroughEPICenter®andSecurityAppliances

ExtremeNetworksEPICenternetworkmanagementapplicationcanapplyTclscriptsforautomationofnetworkeventswhichcancontrolmanyswitches.Networkadministratorshavetheabilitytoaddtheirowncustomfeatures,whethertheyareverysimpleorextremelycomplex,throughscripts.TheonlyknowledgeneededisthesequenceofCLIcommandsneededtodoatask.Administratorscanrapidlycreateanddeploycustomfeaturesandtasksasneeded.HumanExtensibility:WidgetsDistributionthroughWidgetCentral

WidgetCentralisExtremeNetworksportalfordistributionofthewidgetsanddisseminationofextensibilityknowledge.YoucanaccessWidgetCentralat:http://www.extremenetworks.com/solutions/widget-central.