【英文标准名称】:Informationtechnology-Telecommunicationsandinformationexchangebetweensystems-Provisionoftheconnection-modeNetworkinternallayerservicebyintermediatesystemsusingISO/IEC8208,theX.25PacketLayerProtocol
【原文标准名称】:信息技术.系统间的电信和信息交换.使用ISO/IEC8208X.25包层协议通过中间系统提供连接方式网络内层服务
【标准号】:BSISO/IEC10177-1993
【标准状态】:现行
【国别】:英国
【发布日期】:1993-10-15
【实施或试行日期】:1993-10-15
【发布单位】:英国标准学会(GB-BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:开放系统互连;网络层;数据传输;数据传送;信息交流;数据包;通信规程;包交换网络;数据处理;合格
【英文主题词】:Dataprocessing;Datatransfer;Informationinterchange;Informationtechnology;Networkinterconnection;Networklayers;Packetswitchingnetworks;Telecommunications;X.25
【摘要】:ThisInternationalStandardspecifiesthemethodbywhichaNetwork-layerinterworkingunit(IWU)usestheX.25packetlayerprotocolspecifiedinISO/IEC8208tosupporttheOSIconnection-modeNetworkservice.ThespecificationisexpressedintermsofamappingbetweentheNetworkinternallayerservicedefinedinISO/IEC10028andtheVirtualCall(VC)andPermanentVirtualCircuit(PVC)servicesoftheX.25packetlayerprotocol.AnIWUtowhichthisInternationalStandardappliesinterconnects,foranyindividualNetworkconnection,tworealsubnetworks,atleastoneofwhichisaccessedusingtheX.25packetlayerprotocol.WhenbothsubnetworksareaccessedusingtheX.25packetlayerprotocol,thespecificationappliesindependentlytotheIWU'soperationoneachsubnetwork.Inaddition,thisInternationalStandardusesISO/IEC10028'sdefinitionoftherelayingfunctionsofanintermediatesystemtoextenditsapplicationbeyondasinglesubnetworkpointofattachment,tospecifytherequirementstobemetbyanIWUasawholeinsupportingtheOSIconnection-modeNetworkservice.ThisInternationalStandardcoversoperationoftheX.25packetlayerprotocolthatiscompatiblewiththe1984andlaterversionsofCCITTRecommendationX.25,andthatiscompatiblewiththe1980versionofX.25whenthePermanentVirtualCircuitserviceisused;compatibilitywiththe1980versionofX.25forVirtualCallsisoutsidethescopeofthisInternationalStandard.ToenableuseofthePVCservice,thisInternationalStandarddefinesasetofsubnetworkdependentconvergenceprotocol(SNDCP)procedures.TheseallowagivenPVCtotosupportoneNetworkconnectionatatime,buttosupportdifferentNetworkconnections,withthesameordifferentvaluesforaddressandqualityofserviceparameters,etc,atdifferenttimes.TheproceduresalsoallowforthepossibilityofusingaPVCinsupportofotherprotocols,butnotsimultaneouslywiththeseprocedures(apartfromtransientcollisioncases,whichdonotfailunnecessarily).Toevaluateconformanceofaparticularimplementation,itisnecessarytohaveastatementofwhichcapabilitiesandoptionshavebeenimplemented.SuchastatementiscalledaProtocolImplementationConformanceStatement(PICS),asdefinedinISO/IEC9646-1.ThisInternationalStandardprovidesthePICSproformaincompliancewiththerelevantrequirements,andinaccordancewiththerelevantguidance,giveninISO/IEC9646-2.ThisInternationalStandarddoesnotspecifyanyrequirementsrelatingtotheexchangeofroutinginformationorlayer-managementinformationbetweenanIWUandothersystems.
【中国标准分类号】:L78
【国际标准分类号】:33_040_40;35_110
【页数】:36P;A4
【正文语种】:英语