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1、SS7 Training(GSM)(From Basic to Advance)(From Basic to Advance)ContentsIntroduction to SS7Explanation on each layer in GSM SS7 NetworkMAP Operation ExampleExample 1aLocation Update (Overview)Example 1bLocation Update (Message generated in each layer)Call Management ExampleExample 2aMobile Originatin
2、g Call (Overview)Example 2bMobile Originating Call (Message generated in each layer)Future Development of SS7 SS7 Over IP2Introduction to SS7What is SS7 ?Signaling System No.7 (SS7) is a global standard for telecom defined by the International Telecommunication Union (ITU)SS7 is a kind of common cha
3、nnel signaling system which means that signaling network is independent of the speech/data networkSS7 defines the procedures & protocol by which network elements in both the PSTN & Mobile Network exchange information for call setup, call routing & call controlSS7 also defines the protocol for mobili
4、ty management in Mobile Network4SS7 in GSMSS7 in GSM network is responsibility forBasic call setup, management & tear downMobility management - Mobile Subscriber Authentication, Roaming,Location Update, Handover etcSupplementary ServicesCall Forwarding, Calling Number Display, SMS5SS7 Architecture f
5、or GSM6Explanation on each layerin GSM SS7 Network- MTP Layer -MTP StructureMTP layer is divided into 3 sub-layers8- MTP Layer -MTP Layer 1MTP layer is divided into 3 sub-layersLayer 1 defines the physical, electrical & functional characteristics of the signaling link.(e.g. E1, T1)9- MTP Layer -MTP
6、Layer 2MTP layer is divided into 3 sub-layersLayer 2 ensures accurate end-to-end transmission of a message cross a signaling link. It implements flow control, msg. sequence validation & error checking10- MTP Layer -Signal Units in MTP Layer 23 kinds of signal units1.FISU2.LSSU3.MSU11- MTP Layer -Sig
7、nal Unit - FISU3 kinds of signal units1.FISU2.LSSU3.MSUFISUs are transmitted continuously if no LSSU or MSU in the link.Functions1.Acknowledgment of received SU2.Signaling link quality checking12- MTP Layer -Signal Unit - LSSU3 kinds of signal units1.FISU2.LSSU3.MSULSSU carry 1 or 2 octets of link s
8、tatus info between SP at either of a linkFunctions1.To indicate the status of a SP2.To control link alignment13- MTP Layer -Signal Unit - MSU3 kinds of signal units1.FISU2.LSSU3.MSUMSUs carry all call control, database query & response, network management in SIFFunctions1.Call control2.Network manag
9、ment14- MTP Layer -MTP Layer 3MTP layer is divided into 3 sub-layersLayer 3 provides message routing between signaling points in the SS7 network15- MTP Layer -MTP Layer 3 Message16- MTP Layer -MTP Layer 3 MessageNational or International17- MTP Layer -MTP Layer 3 MessageNational or InternationalSCCP
10、 = 3ISUP = 518- MTP Layer -MTP Layer 3 MessageNational or InternationalSCCP = 3ISUP = 5Signal Link Selection- ensure msg. seq.- load sharing19- SCCP Layer -Services ProvidedProvides Connectionless & Connection-oriented Network ServicesPerforms Global Title Translation (GTT)SPC + SSN GT (refer to nex
11、t page)4 Classes of ServicesClass 0 Basic Connectionless ServiceClass 1 Sequenced Connectionless (the same SLS in MTP)Class 2 Basic Connection-orientedClass 3 Flow Control Connection-orientedMAP20- SCCP Layer -Global Title TranslationUser dataSCCPNode ASPC=10GT=85291111111MTPSCCPNode BSPC=20GT=85292
12、2222222MTPSCCPNode CSPC=30GT=852933333333MTPUser dataRoute by GTRoute by GTGT=85293333333GT=85293333333DPC=20OPC=10DPC=20OPC=10DPC=30OPC=20DPC=30OPC=20MSUMSU21- TCAP Layer -Services ProvidedProvides a structured method to request processing of an operation at a remote nodeDefines the information flo
13、w to control the operation & the reporting of its resultCSL Component Sub LayerCSL Component Sub LayerTSL - Transaction sub layerTSL - Transaction sub layerCSLTSLTCAPTCAP is sub-divided into two sub-layersCSL manages componentCSL manages componentTSL manages transaction TSL manages transaction messa
14、gesmessages22- MAP Layer -Services ProvidedA user of TCAPProvides the capability for all Mobile Network Sub-elements (MSC, VLR, HLR, EIR, BSS) to exchange of informationOperations supported by MAPLocation Registration & CancellationSupplementary services provisionSubscriber parameter managementHando
15、ver of established calls etc.23- ISUP Layer -Services ProvidedA user of MTPA protocol & procedures used to set-upmanagerelease trunk circuitsthat carry voice & data calls overSupport both Voice & Non-Voice traffic24Example 1aLocation Update(Overview)MAP Operation Example Location Update OverviewHLRB
16、SSMSC/VLR26 Location Update OverviewHLRBSSMSC/VLRPower On27 Location Update OverviewHLRBSSMSC/VLRChannelAssignment28 Location Update OverviewHLRBSSMSC/VLRLocation Update request29 Location Update OverviewHLRBSSMSC/VLRIMSI request30 Location Update OverviewHLRBSSMSC/VLRIMSI number31 Location Update O
17、verviewHLRBSSMSC/VLRrequest subscriber data32 Location Update OverviewHLRBSSMSC/VLRinsert subscriber data33 Location Update OverviewHLRBSSMSC/VLRAuthentication34 Location Update OverviewHLRBSSMSC/VLRAuth. Response35 Location Update OverviewHLRBSSMSC/VLRUpdate Location36 Location Update OverviewHLRBS
18、SMSC/VLRUpdate LocationHow can MSC generate this “Update Location” Message?37Example 1bLocation Update( (Message generated in each layer) )MAP Operation Example Location Update Message generated in each layerHLRMSC/VLRUpdate LocationMSUMSC generates the “Update Location” message layer by layer. At l
19、ast, a Message Signal Unit (MSU) is generated & sent to the HLR39 Location Update Message generated in MAP layerMSC/VLROperation code = Update LocationMAP MessageIMSI no. = 454100200042300MSC no. = 852 92143999VLR no. = 852 9214399940 Location Update Message generated in MAP layerMSC/VLRMAP Message(
20、Op. code, IMSI etc)41 Location Update Message generated in TCAP layerMSC/VLRTCAPMAP Message(Op. code, IMSI etc)Component portionTransaction portionTransaction ID = 12345678942 Location Update Message generated in TCAP layerMSC/VLRTCAPMAP Message(Op. code, IMSI etc)Component portionTransaction portio
21、nTran. ID = 12345678943SCCP Location Update Message generated in SCCP layerMSC/VLRTCAPMAP Message(Op. code, IMSI etc)Component portionTransaction portion(Tran. ID = 123456789)Message Type = 9(for unit data)Called partyaddressCalling partyaddress44SCCPCalled & Calling party addressMessage Type = 9 (u
22、nit data) Location Update Message generated in SCCP layerMSC/VLRTCAPMAP Message(Op. code, IMSI etc)Component portionTransaction portion(Tran. ID = 123456789)45MTP (SIF)SCCPCalled & Calling party addressMessage Type = 9 (unit data) Location Update Message generated in MTP layer 3MSC/VLRTCAPMAP Messag
23、e(Op. code, IMSI etc)Component portionTransaction portion(Tran. ID = 123456789)DPCOPCSLS46MTP (SIF)DPC, OPC, SLSSCCPCalled & Calling party addressMessage Type = 9 (unit data) Location Update Message generated in MTP layer 3MSC/VLRTCAPMAP Message(Op. code, IMSI etc)Component portionTransaction portio
24、n(Tran. ID = 123456789)47 Location Update Message generated in MTP layer 2MSC/VLRMTP (SIF)SCCPTCAPMAP48 Location Update Message generated in MTP layer 2MSC/VLRMTP (SIF)SCCPTCAPMAP0111 111049 Location Update Message generated in MTP layer 2MSC/VLRMTP (SIF)SCCPTCAPMAP0111 11103-63 for MSU50 Location U
25、pdate Message generated in MTP layer 2MSC/VLRMTP (SIF)SCCPTCAPMAP0111 11103-63 for MSUsubservice + service indicatorSCCP = 3ISUP = 5Last message receivedby receiverSequence number of sendercheck sum51 Location Update MSU completedThe MSU can be sent now ! ! !52Example 2aMobile Originating Call(Overv
26、iew)Call Management Example- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriber54- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberPhone to PSTN55- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscrib
27、erChannelAssignment56- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberCall setup57- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberAnalysis & routing in MSC(e.g. pre-analysis, digit analysis)58- Mobile Originating Call -Overvi
28、ewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberIAMInitiate Address Message59- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberDetermine whether it serves the called party. If yes, it rings the called party line60- Mobile Originating Call -OverviewBSSMSC/VLRP
29、STNSwitchCallingSubscriberPSTNSubscriberACMAddress Complete Message61- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberMSC rings the calling party & connects it to the voice trunk62- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscri
30、berPick Up the phone63- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberANMAnswer Message64- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberchatting65- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNS
31、ubscriberRelease the call66- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberRELRelease Message67- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberDisconnect the trunk from called party68- Mobile Originating Call -OverviewBSSMSC
32、/VLRPSTNSwitchCallingSubscriberPSTNSubscriberRLCRelease Complete Message69- Mobile Originating Call -OverviewBSSMSC/VLRPSTNSwitchCallingSubscriberPSTNSubscriberSet the trunk to idle70Example 2bMobile Originating Call( (Message generated in each layer) )Call Management Example- Mobile Originating Cal
33、l -Message generated in each layerMSC/VLRIAMMSUMSC generates the IAM message by ISUP & MTP layers. At last, a Message Signal Unit (MSU) is generated & sent to the PSTNPSTNSwitch72- Mobile Originating Call -Message generated in ISUP layerMSC/VLRCICISUP MessageCalling party numberMessage Type = IAMCal
34、led party number73- Mobile Originating Call -Message generated in ISUP layerMSC/VLRISUP Message(IAM, CIC, Called party,Calling party)74MTP (SIF)- Mobile Originating Call -Message generated in MTP layer 3MSC/VLRDPCOPCSLSISUP Message(IAM, CIC, Called party,Calling party)75MTP (SIF)DPC, OPC, SLS- Mobil
35、e Originating Call -Message generated in MTP layer 3MSC/VLRISUP Message(IAM, CIC, Called party,Calling party)76- Mobile Originating Call -Message generated in MTP layer 2MSC/VLR0111 11103-63 for MSUsubservice + service indicatorSCCP = 3ISUP = 5Last frame receivedby receiverSequence number of senderM
36、TP (SIF)ISUP Message(IAM, CIC, Called party,Calling party)check sum77- Mobile Originating Call -MSU completedThe MSU can be sent now ! ! !78MTP Route (1)C7 Link:SR - Signalling Route (End to End)LS - Linkset (point to point)SL - Signalling Link (point to point)SW1 DestinationSTP-1STP-2SLsSLsSW1STP1S
37、TP3STP2STP4DestinationSR (logical)LS (logical)SL (physical)79MTP Route (2)Signalling Capturee.g. CMB 9197 to Tunisia 4533Message #7星期六 06 六月 2009 07:19:43.0187; InsertSubscriberData-NormalTCAP TransactionCMB (9197,0) - STP4 ID3 (9609,0) - 11CMB (9197,0)4553, 0MAP80SS7 Over IPSS7 Over IPAdvantageBetter use of available bandwidthCheaper costImplementation MethodReplace the MTP layers by two new adaptation layers (M3UA, SCTP) & the IP layer82The End
