9 Internal UseService Functions of SCCP Network There are two kinds of service provided by the SCCP protocol: Connectionless Service 0.. 11 Internal UseConnectionless Service The c
Trang 1Huawei Confidential All Rights Reserved
OMF001005 GSM Signaling System-SCCP(BSS)
ISSUE 2.0
Trang 22 Internal Use
Objective
Upon completion this course, you are
supposed to be able to:
Understand the necessity of SCCP.
Know the services provided by SCCP.
Know the SCCP message format.
Trang 33 Internal Use
Chapter 1 General Chapter 2 Features & Functions of SCCP Chapter 3 Addressing & Routing Functions of SCCP Chapter 4 SCCP Message Format
Trang 44 Internal Use
Limitation of MTP Transmission
The signaling point code is not the standard international code,
it is only effective within a certain network.
The limited capacity of the signaling point code (14-bit is specified by CCITT) also limits the number of the signaling point
to be marked.
The 4-bit SI can not satisfy the increased requirements of the modern communication as well, since it can only be assigned to sixteen different user parts.
MTP can only provide the connectionless transmission
Trang 66 Internal Use
Chapter 2 Features & Functions of SCCP
Section 1 Application Features of SCCP
Section 2 Service Functions of SCCP Network
Trang 7 Enable to provide both connectionless service and connection-oriented service.
Trang 88 Internal Use
Chapter 2 Features & Functions of SCCP
Section 1 Application Features of SCCP
Section 2 Service Functions of SCCP Network
Trang 99 Internal Use
Service Functions of SCCP Network
There are two kinds of service provided by the SCCP protocol:
Connectionless Service
0 Basic connectionless class
1 In-sequence delivery connectionless class
Connection-oriented Service
2 Basic connection-oriented class
3 Flow control connection-oriented class
Trang 1111 Internal Use
Connectionless Service
The connectionless SCCP offers two services:
The class 0 service allows the SCCP to insert SLS values rando mly, or with the aim to achieve an appropriate load sharing with
in the underlying MTP network.
The class 1 service requires the SCCP to insert the same SLS f
or all the SCCP-SDUs (service data unit) associated with given parameters "sequence control" and "called address"
Trang 1212 Internal Use
Connectionless Service
UDT unit data UDTS unit data service XUDT extended unit data XUDTS -extended unit data service
Message type UDT UDTS XUDT XUDTS Message type code 0x09 0x0A 0x11 0x12
Trang 1313 Internal Use
SCCP procedure of connectionless service
originating SCCP SCCP relay
terminal SCCP
UDT UDTS failure
Connectionless Service
Trang 1414 Internal Use
Connection-oriented Service
Connection-oriented service is a way to realize the exchange of signaling information by establishing a logical signaling connection between the network service users.
The logical signaling connection is achieved by distributing a local reference number to the signaling messages belonging together.
Trang 1515 Internal Use
originatingSCCP
relaySCCP
terminalSCCP
Trang 1616 Internal Use
Chapter 1 General Chapter 2 Features & Functions of SCCP Chapter 3 Addressing & Routing Functions of SCCP Chapter 4 SCCP Message Format
Trang 1717 Internal Use
Addressing and Routing Functions of SCCP
Address in SCCP comprises three elements:
DPC Global Title (GT) Sub-System Number (SSN)
Trang 1818 Internal Use
0000 0000 SSN not known/not used
0000 0001 SCCP management
0000 0010 Reserved for ITU-T allocation
0000 0011 ISDN user part£ ¨ISUP£ ©
0000 0100 Operation, maintenance and administration part (OMAP)
0000 0101 Mobile application part£ ¨MAP£ ©
0000 0110 Home location register£ ¨HLR£ ©
0000 0111 Visitor location register£ ¨VLR£ ©
0000 1000 Mobile switching centre£ ¨ MSC£ ©
0000 1001 1111 1101 Idle
1111 1110 BSS Application Part (BSC)
1111 1111 Reserved for expansion of national and international SSN
SSN
Trang 1919 Internal Use
There are two basic categories of SCCP routing
GT
DPC+SSN Addressing and Routing Functions of SCCP
Trang 2020 Internal Use
From SPA to SPD,
If DPC+SSN routing is adopted by SCCP, in the Called Party Address of SCCP message, DPC is point code of SPD, while SSN depends on the different requirements The message is sent to STPB or STPC, the Called Party Address is not necessary to be translated by STP.
If GT routing is adopted by SCCP, in the Called Party Address of SCCP message, GT
is the information of SPD Because GT can’t be identified by MTP, actually, DPC should be included in the SCCP message, in this case, DPC is point code of STP The message is sent to STPB or STPC, the Called Party Address is necessary to be translated to the relevant point code and/or SSN by STP
Trang 2121 Internal Use
Chapter 1 General Chapter 2 Features & Functions of SCCP Chapter 3 Addressing & Routing Functions of SCCP Chapter 4 SCCP Message Format
Trang 22Pointer to parameter P Pointer to start of optional part Length indicator of parameter M Parameter M
…………
Length indicator of parameter P Parameter P
Parameter name=X Length indicator of parameter X Parameter X
…………
Parameter name=Z Length indicator of parameter Z Parameter Z
End of optional parameters
8 16 8n,n>2 8 2 6 1 7 1 7 8
Routing label Message type Mandatory fixed part (F) Mandatory variable part (V) Optional part (O)
Trang 23Called party address pointer Calling party address party Data pointer
Called party address length Called party address
Calling party address length Calling party address
Data length Data (TCAP)
MF
MVMVMV
Trang 2424 Internal Use
Summary
Summary
Trang 25Huawei Confidential All Rights Reserved