下一代网络媒体网关数据路径的研究与实现

上海交通大学硕士学位论文下一代网络媒体网关数据路径的研究与实现姓名：陈新申请学位级别：硕士专业：计算机应用技术指导教师：白英彩20050101IIINGNIPNGNNGNVoIPNGNVoIPH.323SIPH.248/MEGACOH.323SIPH.248/MEGACOH.248/MEGACONGNH.248/MEGACOGCPTDMVPDSPNPUDSPNPUNGNH.248/MEGACOIVResearchandImplementationofMediaGatewayDataPathinNGNABSTRACTGlobaltelecomindustryisundergoingtheinnovationfromthetraditionalnetworktothenextgenerationnetwork(NGN)nowadays.Comparedwiththetraditionalnetwork,theNGNisanopenplatformbasedonIPnetwork,whichisakindofwholeservicenetworkprovidingserviceofvoice,dataandmultimedia,eitherseparatelyorintegratedly.ThedevelopmentoftheNGNisunderevolution,whichinheritstheadvantagesofthetraditionalnetworkandistransittingintothecompleteNGNgradually.VoIPisstillthemostimportantprofitableserviceintheNGNatpresent.Inthissituation,mediagatewayplaysanimportantroleincombiningthetraditionalnetworkandtheNGN.Itcantransformthemediastreamformatofonenetworkintotheothertypefittinganotherkindofnetwork.TherearethreemajorprotocolsrelatedtotheVoIPservice:H.323,SIPandH.248/MEGACO.H.323andSIParethepeertopeerprotocolswhileH.248/MEGACOisnotthepeertopeerprotocol.H.248/MEGACOworksinmaster/slavemode,thatis,thecallcontrolwillbeprocessedbythemediagatewaycontroller(MGC),whilethemediagatewaywillonlyprocessthemediainformation.ThisstructuresatisfiestheNGN’sseparatingprinciplebetweencontrollayerandbearlayer,whichisanimportanttrendoffuturedevelopment.ThisdissertationintroducesthedesignandimplementationofakindofmediagatewaycontrolledbyH.248/MEGACOprotocol,intermsofthefunctionalmodel,physicalmodel,softwarearchitecture,andthedesignandimplementationofGCPapplication,particularly,focusingonthemodulesincludingTDMManager,ResourceManagerandVoicePortManager,whicharedirectlyrelatedtothesetupofdatapath.Thisdissertationalsoprovidestheuniversalinterfaceforthecontrolofmediagateway,maskingthediversitiesbetweengatewaycontrolprotocols,whichwillbenefittheexpansionintheapplicationlayer.Finally,thisdissertationgivesanintroductionoftheprocessofVsettinguptheinternaldatapathofthemediagateway.Inordertokeepthebalanceamongthemicroprocessor,DSPandNPU,differentgatewayneedsdifferentdatapathrealizationpolicy,accordingtothesituationofdifferentgatewaycapability,andperformanceetc.Therefore,thisdissertationcomparesdifferentimplementationofmediagatewaydatapath,andputsforwardthekeymethodologyofsettingupthedatapathfromDSPtoNPU.KEYWORDS:NGN,H.248/MEGACO,MediaGateway,DataPathIX1-1NGN............................................................................................21-2NGN............................................................................................42-1...........................................................................................92-2.............................................................................................132-3..........................................................132-4MG............................................................................................152-5MG..........................................................................................162-6MGC..........................................................................................162-7MGC........................................................................172-8.....................................................................................172-9.....................................................................182-10...................................................................................182-11............................................................................192-12AddTDM,AddRTP()...........................................202-13AddTDM,AddRTP().......................212-14H.323....................................................................................213-1..........................................................................333-2Pizzabox................................................................................343-3Pizzabox............................................................................353-4Pizzabox................................................................................363-5Pizzabox....................................................................................363-6Pizzabox....................................................................................363-7Pizzabox................................................................................373-8Pizzabox................................................................................384-1GCP..................................................................................414-2TAPA................................................................................................424-3GCP..............................................................................424-4GCP..............................................................................434-5GCPAPPL................................................................................444-6MgMgcoMsg..........................................................