m3ua讲课用

ASP-DOWN:TheremoteM3UApeerattheASPisunavailableand/ortherelatedSCTPassociationisdown.InitiallyallASPswillbeinthisstate.AnASPinthisstateSHOULDNOTbesentanyM3UAmessages,withtheexceptionofHeartbeat,ASPDownAckandErrormessages.ASP远端M3UA对等体不可用或者相关的SCTP偶联没有建立。初始时所有的ASP都处于此状态。一个ASP在这个状态不能发送任何M3UA消息，除了心跳、ASPDOENACK和ERROR消息。ASP-INACTIVE:TheremoteM3UApeerattheASPisavailable(andtherelatedSCTPassociationisup)butapplicationtrafficisstopped.InthisstatetheASPSHOULDNOTbesentanyDATAorSSNMmessagesfortheASforwhichtheASPisinactive.ASP-ACTIVE:TheremoteM3UApeerattheASPisavailableandapplicationtrafficisactive(foraparticularRoutingContextorsetofRoutingContexts).SCTPCDI:TheSCTPCDIdenotesthelocalSCTPlayer'sCommunicationDownIndicationtotheUpperLayerProtocol(M3UA)onanSGP.ThelocalSCTPlayerwillsendthisindicationwhenitdetectsthelossofconnectivitytotheASP'speerSCTPlayer.SCTPCDIisunderstoodaseitheraSHUTDOWN_COMPLETEnotificationorCOMMUNICATION_LOSTnotificationfromtheSCTPlayer.SCTPRI:ThelocalSCTPlayer'sRestartindicationtotheupperlayerM3UA_LINK_INACTIVEM3UA_LINK_UNESTABLISHM3UA_LINK_DOWNAspInactive/AspInactiveAck/AspAltNotifyAspActive/AspActiveAckM3UAbackoutsuccessful/Sctp-CDIM3UA_LINK_ACTIVESCTP-RIAspDownorAspDownAckorSCTP-RISCTP-CDISCTPCDIM3UAestablishsuccessfulAspUporAspUpAckprotocol(M3UA)onanSG.ThelocalSCTPwillsendthisindicationwhenitdetectsarestartfromtheASP'speerSCTPlayer.AS-DOWN:TheApplicationServerisunavailable.ThisstateimpliesthatallrelatedASPsareintheASP-DOWNstateforthisAS.InitiallytheASwillbeinthisstate.AnApplicationServerisintheAS-DOWNstatewhenitisremovedfromaconfiguration.AS-INACTIVE:TheApplicationServerisavailablebutnoapplicationtrafficisactive(i.e.,oneormorerelatedASPsareintheASP-INACTIVEstate,butnoneintheASP-ACTIVEstate).TherecoverytimerT(r)isnotrunningorhasexpired.ASPUpTheASPUpmessageisusedtoindicatetoaremoteM3UApeerthattheadaptationlayerisreadytoreceiveanyASPSM/ASPTMmessagesforallRoutingKeysthattheASPisconfiguredtoserve.ASPUpAcknowledgement(ASPUpAck)TheASPUPAckmessageisusedtoacknowledgeanASPUpmessagereceivedfromaremoteM3UApeer.SCCPTransportbetweenIPSPs********IP*********IPSP**IPSP*****************+------++------+|SCCP-||SCCP-||User||User|+------++------+|SCCP||SCCP|+------++------+|M3UA||M3UA|+------++------+|SCTP||SCTP|+------++------+|IP||IP|+------++------+|________________|M3UA链路集：SGP和ASP之间的多条链路组成一个链路集。一个链路集的所有链路为同一个AS服务。链路集当中链路的状态决定链路集的状态。ASP的链路集有三种状态：DOWN、INACTIVE、ACTIVE。SGP的链路有四种状态：DOWN、INACTIVE、PENDING、ACTIVE。MGW中的M3UA工作为SGP。链路集处于DOWN状态表示链路集中的所有链路处于DOWN或UNESTABLISH状态。链路集处于INACTIVE状态表示链路集中没有一条链路处于ACTIVE状态，但至少有一条链路处于INACTIVE状态。链路集处于ACTIVE状态表示链路集中的链路至少有一条处于ACTIVE状态。链路集处于PENDING状态表示链路中的最后一条处于ACTIVE状态的链路变为非ACTIVE状态，此时SGP的M3UA实体启动一个PENDING定时器，同时缓存收到报文。如果在定时器超时前，链路集中有链路恢复为ACTIVE状态，则链路集恢复为ACTIVE状态，同时将缓存的报文发送出去。如果定时器超时，链路集状态迁移至DOWN、INACTIVE状态（根据链路集中链路的状态）。M3UA路由：从源实体到目的实体的路径称之为路由。一条路由对应一个链路集，多条路由可以对应到同一个链路集上。源实体和目的实体间可以存在多条路由。路由有两种状态：可达、不可达。在SGP中，路由状态完全依赖于链路集的状态，链路集处于ACTIVE或PENDING状态，路由可达，否则，路由不可达。在ASP中，路由状态依赖于链路集状态和SG到SS7网络的状态。M3UA链路有四种状态：UNESTABLISH、DOWN、INACTIVE、ACTIVE。链路处于UNESTABLISH状态表示SGP和ASP间尚未建立起SCTP连接。链路处于DOWN状态表示SCTP连接已经建立好，但是还没有完成M3UAdraft07中的ASPUP过程。链路处于INACTIVE状态表示已经完成了ASPUP的过程，但是还没有完成ASPACTIVE的过程。链路处于ACTIVE状态表示已经完成了ASPACTIVE的过程，具体的状态迁移过程参照协议M3UAdraft07。