Chuyên đề Mạng truyền dẫn quang (TS. Võ Viết Minh Nhật) - Bài 9 Kỹ thuật báo hiệu trên mạng OBS

Bài này nhằm cung cấp cho học viên các kiến thức và kỹ năng về:các giải thuật báo hiệuone-way, two-way, or hybrid reservationsource-initiated, destination-initiated, or intermediate-node-initiated reservationpersistent or non-persistent reservationimmediate or delayed reservationexplicit or implicit release of resourcescentralized or distributed signaling
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Chuyên đề Mạng truyền dẫn quang (TS. Võ Viết Minh Nhật) - Bài 9 Kỹ thuật báo hiệu trên mạng OBSChuyênđê: Mạng truyền dẫn quangBài 6: Kỹ thuật báo hiệu trên mạng OBS TS.VõViếtMinhNhật KhoaDuLịch–ĐạihọcHuế vominhnhat@yahoo.com 1Mục tiêuo Bàinàynhằmcungcấpchohọcviêncáckiếnthứcvàkỹnăngvề:  cácgiảithuậtbáohiệu • oneway,twoway,orhybridreservation • sourceinitiated,destinationinitiated,orintermediatenodeinitiatedreservation • persistentornonpersistentreservation • immediateordelayedreservation • explicitorimplicitreleaseofresources • centralizedordistributedsignaling 2Nội dung trình bàyo Introductiono oneway,twoway,orhybridreservationo sourceinitiated,destinationinitiated,orintermediatenode initiatedreservationo persistentornonpersistentreservationo immediateordelayedreservationo explicitorimplicitreleaseofresourceso centralizedordistributedsignaling 3Introductiono Asignalingschemeisimplementedinordertoallocateresources andtoconfigureopticalswitchesfortheburstateachnode.o ThesignalingschemeinanOBSnetworkistypicallyimplemented usingoutofbandburstheaderpackets. 4Classification of Signaling Schemeso oneway,twoway,orhybridreservationo sourceinitiated,destinationinitiated,orintermediatenode initiatedreservationo persistentornonpersistentreservationo immediateordelayedreservationo explicitorimplicitreleaseofresourceso centralizedordistributedsignaling 56One-way, Two-way, or Hybrido Inonewayreservation  thesourcenodesendsoutacontrolpacketrequestingeachnodeinthe routetoallocatethenecessaryresourcesandtoconfiguretheircross connects  thedataburstisthensentoutwithoutwaitingforanacknowledgement  itispossiblethatthereservationswerenotsuccessfulandtheburstis dropped.  But,thedataburstcanbesentoutsooner,therebyreducingtheendto enddatatransferlatency 7One-way, Two-way, or Hybrido Intwowayreservation  Signalingtechniquesareacknowledgmentbased  Thedataburstistransmittedonlyaftertheacknowledgementisreceived  ThesesignalingtechniquescaneliminatethelossofburstsintheOBS core,butwillalsoleadtohigherendtoenddelayforeachburst 8One-way, Two-way, or Hybrido Inhybridreservation  atradeoffbetweenonewayandtwowayreservationsistoprovide partialconfirmationofreservations. 9Source-, Destination-, Intermediate-Node-Initiated Reservationo Sourceinitiatedreservation(SIR)  theresourcesfortheburstarereservedintheforwardpathastheburst headertravelsfromthesourcetothedestination.  aconfirmedreservationtechniqueisusedinwhichanacknowledgment messageindicatingthereservedwavelengthsissentbacktothesource  itmaycauseofblocking(ordataloss)becauseofthelackoffreeresources 10Source-, Destination-, Intermediate-Node-Initiated Reservationo Destinationinitiatedreservation(DIR)  thesourcetransmitsaresourcerequesttothedestinationnodetocollect wavelengthavailabilityinformation  thedestinationnodethenwillchooseanavailablewavelength(ifsuch exists)fortheappropriatetimeinterval,andsendareservationrequest backtothesource.  Thereservationrequestwilltraversetheintermediatenodes,reservingthe chosenwavelengthfortheappropriateperiodoftime  itmaycauseofblocking(ordataloss)becauseofoutdatedinformation 11Source-, Destination-, Intermediate-Node-Initiated Reservationo intermediatenodeinitiatedreservation(INI)  theresourcesarereservedsimilartoDIRfromthesourcetosome intermediatenode,andsimilartoSIRfromtheintermediatenodetothe destinationnode.o toreducetheloss  SIRtechniquesmayreservemorethanone(orallavailable)wavelengths =>lowerperformanceduetolackofresources.  InDIRtechniques,becausetheindividualstateinformationreceivedare notuptodatetheselectedwavelengthmaybeta ...