DRAFT 1.9 W. B. Norton Internet Service Providers and Peering

Internet Service Provider (ISP) peering has emerged as one of the most important and effective ways for ISPs to improve the efficiency of operation. Peering is defined as “an interconnection business relationship whereby ISPs provide connectivity to each

DRAFT1.9W.B.Norton

InternetServiceProvidersandPeeringWilliamB.Norton<wbn@http://www.51wendang.com>

Abstract

InternetServiceProvider(ISP)peeringhasemergedasoneofthemostimportantandeffectivewaysforISPstoimprovetheefficiencyofoperation.Peeringisdefinedas“aninterconnectionbusinessrelationshipwherebyISPsprovideconnectivitytoeachothers’transitcustomers.”ISPsseekpeeringrelationshipsprimarilyfortworeasons.First,peeringdecreasesthecostandrelianceonpurchasedInternettransit.Asthesinglegreatestoperatingexpense,ISPsseektominimizethesetelecommunicationscosts.Second,peeringlowersinter-AutonomousSystem(AS)trafficlatency.ByavoidingatransitproviderhopinbetweenISPstrafficbetweenpeeringISPshaslowerlatency.Sohowispeeringdone?

ThispaperdetailstheISPpeeringdecision-makingprocess.InterviewswithInternetServiceProviders1havehighlightedthreedistinctdecisionphasesofthepeeringprocess:Identification(TrafficEngineeringDataCollectionandAnalysis),Contact&Qualification(InitialPeeringNegotiation),andImplementationDiscussion(PeeringMethodology).Thefirstphasesidentifiesthewhoandthewhy,whilethelastphasefocusesonthehow.

TheappendixincludesthedescriptionofaPeeringSimulationGamethathasbeenusedinworkshopstoplayoutpeeringnegotiations.

IntroductionandDefinitions

InternetServiceProviders(ISPs)connectend-usersandbusinessestothepublicInternet.Theycompetewitheachotheronprice,performance,reliability,etc.buttheyalsomustcooperatewitheachotherto

provideglobalconnectivitytoallotherattachmentsontheInternet.Thecooperationisexplicitlystatedatdemarcationpointswheretheyinterconnect,calledimprecisely“peeringpoints”.Thisisanimperfectnamesinceinterconnectiontypicallytakesoneoftwoforms:apeeringrelationshiporatransitrelationship,andbothusetheBorderGatewayProtocol(BGP)forroutingannouncementexchange.Problemsarisewhentheterm“peering”isusedinterchangeablywitha“transit”relationship.Tolaythegroundworkforthispaper,weintroducethefollowingworkingdefinitions.

1Interviewswith100ISPsoverthecourseoftwoyears

alongwithpresentationsofthefindingstoISPsatNANOG,RIPEandIEPGsubstantiallyvalidatethefindings.

isthebusinessrelationshipwherebyISPsreciprocallyprovidetoeachotherconnectivitytoeachothers’transitcustomers.Toillustratepeering,considerfigure1belowshowingamuchsimplifiedInternet:theInternetwithonlythreeISPs:WestNet,USNet,http://www.51wendang.comNethas

customersofitsown(beigecircles)andEastNethasitscustomersshownasyellowcircles.

Figure1-PeeringandTransitrelationshipsInthisexample,WestNethasapeeringrelationshipwithUSNetinwhichUSNetannouncesreachabilityofitsbeigecustomerstoWestNet,andWestNetannouncesreachabilitytoitsgreencustomersto

USNet.Thisistheessenceofthepeeringrelationship;eachISPreciprocallyprovidesaccesstoeachotherscustomers.EastNetalsopeerswithUSNet,

announcingitsyellowcustomerstoUSNetwhileUSNetannouncesitsbluecustomerstoEastNet.ItisimportanttonotethatWestNetandEastNetcannotaccesseachotherscustomersinthisconfiguration.(TheboxesbelowtheISPsshowtheirrespectiveroutingtables.)WestNetonlyknowshowtogettoblueandgreencustomers,andEastNetknowshowtoreachonlyblueandyellowcustomers.ThefactthattheybothpeerwithUSNetisinconsequential;peeringisanon-transitiverelationship.

Sincepeeringisareciprocalnon-transitive

relationship,EastNetandWestNetmustpeerwitheveryotherISPorfindanotherwayofaccessingeveryotherISP.

isthebusinessrelationshipwherebyoneISPprovides(usuallysells)accessto

DRAFT 1.9 W. B. Norton Internet Service Providers and Peering

Word文档免费下载Word文档免费下载:DRAFT 1.9 W. B. Norton Internet Service Providers and Peering (共15页,当前第1页)

DRAFT 1.9 W. B. Norton Internet Service Providers and Peering相关文档

最新文档

返回顶部