1、Standard ECMA-265September 1997Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chBroadband Private Integrated ServicesNetwork (B-PISN) -Inter-Exchange Signalling Protocol -Signalling ATM Adaptation L
2、ayer.Standard ECMA-265September 1997Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chIW Ecma-265.doc 03-09-97 17,01Broadband Private Integrated ServicesNetwork (B-PISN) -Inter-Exchange Signalling Pr
3、otocol -Signalling ATM Adaptation Layer(B-QSIG-SAAL).Brief HistoryThis Standard is one of a series of ECMA Standards defining services and signalling protocols applicable to Broadband PrivateIntegrated Services Networks (B-PISNs). The series uses B-ISDN concepts as developed by ITU-T and conforms to
4、 theframework of International Standards for Open Systems Interconnection as defined by ISO/IEC. It has been produced underETSI work item DEN/ECMA-00130.This particular Standard specifies the Signalling ATM Adaptation Layer (SAAL) protocol for use at the Q reference point.This Standard is based upon
5、 the practical experience of ECMA member companies and the results of their active andcontinuous participation in the work of ISO/IEC JTC1, ITU-T, ETSI and other international and national standardizationbodies. It represents a pragmatic and widely based consensus.This ECMA Standard is completely al
6、igned with International Standard ISO/IEC 13246 to be published by ISO/IEC.This ECMA Standard has been adopted by the General Assembly in September 1997.- i -Table of contents1 Scope 12 Conformance 13 References (normative) 14 Definitions 15 List of acronyms 16 Description 26.1 Common Part - AAL Typ
7、e 5 26.2 SSCOP 36.3 SSCF for Broadband Inter-PINX Signalling 37 Operational Requirements 37.1 B-QSIG SAAL Connections 37.2 Traffic Management Method for B-QSIG SAAL Connections 38 B-QSIG SAAL Specification 38.1 Basic Structure 38.2 AAL Type 5 38.3 SSCOP 38.4 SSCF for Broadband Inter-PINX Signalling
8、48.4.1 SAAL Services Provided by the SSCF for B-QSIG Signalling 48.4.2 Functions of the SSCF and Signalling Protocol Stack 48.4.3 Definition of the Boundary of SSCF to B-QSIG-Layer 3 Protocols 48.4.4 Definition of the Boundary of SSCF with SSCOP 48.4.5 State Transition Table of SSCF for Supporting B
9、-QSIG Signalling 48.4.6 Boundary to Layer Management 48.4.7 Applicability of SSCOP Parameters and Timers to B-QSIG Signalling 48.4.8 PICS Proforma for SSCOP AND SSCOP-SSCF 58.4.9 SSCF for Semi-Permanent Connection (SPC) Control Signalling 5Annex A - Protocol Implementation Conformance Statement (PIC
10、S) proforma for B-QSIG SAAL 7Annex B - Relationship to corresponding ITU-T Recommendations for public B-ISDN UNIs 21Annex C - Protocol data unit and related primitive sequences for establishment and release ofB-QSIG SAAL connections 23- ii -.1ScopeThis Standard specifies the signalling ATM adaptatio
11、n layer (SAAL) protocol used at the interface between BroadbandPINXs and between Broadband PISNs within the framework of the B-QSIG signalling system protocol family. TheB-QSIG SAAL uses the functions provided by the ATM layer, and provides the services required by the B-QSIGLayer 3 signalling proto
12、cols.2 ConformanceIn order to conform to this Standard, a PINX shall satisfy requirements identified in the Protocol ImplementationConformance Statement (PICS) in annex A.3 References (normative)The following standards contain provisions which, through reference in this text, constitute provisions o
13、f this Standard.All standards are subject to revision, and parties to agreements based on this Standard are encouraged to investigate thepossibility of applying the most recent editions of the standards indicated below.ISO/IEC 9646-1 Information technology - Open Systems Interconnection - Conformanc
14、e testingmethodology and framework - Part 1: General concepts (1994)ISO/IEC 9646-7 Information technology - Open Systems Interconnection - Conformance testingmethodology and framework - Part 7: Implementation Conformance Statements (1995)ITU-T Rec. I.321 B-ISDN protocol reference model and its appli
15、cation (1991)ITU-T Rec. I.361 B-ISDN ATM layer specification (1995)ITU-T Rec. I.362 B-ISDN ATM Adaptation Layer (AAL) functional description (1993)ITU-T Rec. I.363.5 B-ISDN ATM Adaptation Layer (AAL) specification - Part 5: AAL Type 5 (1996)ITU-T Rec. I.371 Traffic control and congestion control in
16、B-ISDN (1996)ITU-T Rec. Q.2100 B-ISDN Signalling ATM Adaptation Layer (SAAL) overview description (1994)ITU-T Rec. Q.2110 B-ISDN ATM Adaptation Layer - Service Specific Connection Oriented Protocol(SSCOP) (1994)ITU-T Rec. Q.2130 B-ISDN Signalling ATM Adaptation Layer - Service Specific Coordination
17、Function forsupport of signalling at the User-Network Interface (SSCF at UNI) (1994)4 DefinitionsThe definitions of ITU-T Recommendations I.363.5, Q.2110 and Q.2130 apply.5 List of acronymsAAL ATM Adaptation LayerATM Asynchronous Transfer ModeB-ISDN Broadband ISDNB-PINX B-PISN ExchangeB-PISN Broadba
18、nd Private Integrated Service NetworkB-QSIG Broadband QSIGCRC Cyclic Redundancy CheckIPL Inter-PINX-LinkPICS Protocol Implementation Conformance Statement- 2 -PINX Private Integrated Services Network ExchangeSAAL Signalling AALSDU Service Data UnitSPC Semi-Permanent ConnectionSSCF Service Specific C
19、onvergence FunctionsSSCOP Service Specific Connection Oriented ProtocolUBR Unspecified Bit RateUNI User Network Interface6 DescriptionThe SAAL protocol for Broadband Inter-PINX signalling uses the services of the ATM layer and provides the servicesrequired by the B-QSIG Layer 3 signalling protocols.
20、 It is based on the generic framework outlined byRecommendations I.362 for the functional description of the AAL, and Q.2100 for the signalling AAL specification.The B-QSIG SAAL allows a B-QSIG SAAL user (i.e. a layer 3 signalling protocol) to communicate with its peerentity. In particular, it provi
21、des for a reliable transfer of layer 3 signalling messages. The information transfer betweenthe B-QSIG SAAL user and the B-QSIG SAAL uses primitives and is performed in Message Mode.Two peer-to-peer operational procedures are specified: Unassured or Assured operation. The support of the Assuredopera
22、tion is mandatory. The support of Unassured operation is optional.NOTEThe use of unassured operation is not required by the B-QSIG layer 3 signalling protocol.The basic structure of the B-QSIG SAAL is contained in figure 1. For the B-QSIG SAAL, 3 sublayers are definedsimilar to those shown in figure
23、 1 of Rec. Q.2100: SSCF for B-QSIG SSCOP Common Part - AAL Type 5.SSCF for B-QSIG signallingQ.2110 SSCOP(Service Specific Connection Oriented Protocol)I.363.5 AAL type 5Figure 1 - B-QSIG SAAL Structure6.1 Common Part - AAL Type 5AAL Type 5 provides transparent transfer and CRC checking (32 Bits) for
24、 SSCOP SDUs, segmentation into ATMcells, and reassembly.- 3 -6.2 SSCOPSSCOP provides the basic mechanisms for the establishment and release of connections and the reliable exchangeof information between B-PINX peer entities.6.3 SSCF for Broadband Inter-PINX SignallingSSCF maps the particular require
25、ments of the Broadband Inter-PINX layer 3 signalling protocols to the SSCOPservices.7 Operational RequirementsB-QSIG SAAL requires that the following configuration information is available at both sides of an IPL (the methodfor making this information available for both peer entities is outside the
26、scope of this Standard): which virtual channel acts as the signalling channels for the IPL which traffic management method is applied on that virtual channel.7.1 B-QSIG SAAL ConnectionsThe B-QSIG SAAL operates in a connection-oriented mode. The B-QSIG SAAL connection(s) shall be establishedas part o
27、f the IPL establishment, and shall reside permanently (except for error cases).NOTEB-QSIG SAAL connections are established between two peer entities at the two ends of an IPL.7.2 Traffic Management Method for B-QSIG SAAL ConnectionsFor the operation of the B-QSIG SAAL protocol, the peer entities at
28、two ends of an IPL shall be pre-configuredwith the traffic resources allocated to the B-QSIG SAAL connections. For each B-QSIG SAAL connection (or for aset of them together). the following are examples of parameters that can be pre-configured (see also ITU-T Rec.I.371):a) a peak cell rate indication
29、 (only), e.g. 167 cells/sec.b) peak cell rate, sustainable cell rate, and maximum burst size (together)c) an indication as “unspecified bit rate“ (UBR).The method of configuring the traffic resources allocated to the B-QSIG SAAL connection is outside the scope ofthis Standard. However, it is essenti
30、al for the traffic management of B-QSIG SAAL connections that both peerentities at the IPL apply the same allocation of parameters.8 B-QSIG SAAL Specification8.1 Basic StructureClause 5 of ITU-T Rec. Q.2100 applies.8.2 AAL Type 5ITU-T Rec. I.363.5 applies.8.3 SSCOPITU-T Rec. Q.2110 applies.NOTEThe S
31、SCOP can be combined with different Service Specific Coordination Functions (SSCFs) to offer different AALservices. As a result, the SSCOP specification defines mandatory functions for a general protocol. Some of thesefunctions are not needed within B-QSIG SAAL. Therefore, it is possible for an impl
32、ementation not to implement acertain SSCOP function and still meet the mandatory requirements of B-QSIG SAAL (e.g. the SSCOP local dataretrieval function is not needed within B-QSIG SAAL), provided that the SSCOP implementation provides for theservices used by the B-QSIG SAAL-SSCF.- 4 -A fully compl
33、iant SSCOP implementation according to ITU-T Rec. Q.2110 meets the requirements for the SSCOPof this Standard.8.4 SSCF for Broadband Inter-PINX Signalling8.4.1 SAAL Services Provided by the SSCF for B-QSIG SignallingThe following services shall be provided. Unless specified differently, they shall b
34、e provided as specified inclause 5 of ITU-T Rec. Q.2130: assured transfer of data. transparency of transferred information.NOTEThe SSCF does not interpret the structure or meaning of SDUs; as a default, it supports the transfer of octet-aligned SDUs up to a maximum of 4 096 octets. establishment and
35、 release of B-QSIG SAAL connections for assured transfer of data.B-QSIG SAAL connections are established during IPL establishment, and reside permanently. However, incertain error scenarios, the SSCF may release B-QSIG SAAL connections to recover from error situations.The following SAAL services may
36、 optionally be provided: unacknowledged transfer of data.The use of this service is not specified by the B-QSIG layer 3 signalling protocol.8.4.2 Functions of the SSCF and Signalling Protocol StackClause 6 of ITU-T Rec. Q.2130 applies with the following exception: only point-to-point B-QSIG SAAL con
37、nections shall be supported. In particular, B-QSIG SAAL shall notprovide the broadcast capability described in clause 6/Q.2130.8.4.3 Definition of the Boundary of SSCF to B-QSIG-Layer 3 ProtocolsClause 7 of ITU-T Rec. Q.2130 applies with the following exceptions: The support of the AAL-UNITDATA prim
38、itive is not mandatory. The use of this primitive is not specified byB-QSIG layer 3 signalling protocol. The support of layer 3 peer-to-peer messages in the AAL-ESTABLISH and AAL-RELEASE primitives is notmandatory. The use of those parameter data in these primitives is not specified by the B-QSIG la
39、yer 3signalling protocol.8.4.4 Definition of the Boundary of SSCF with SSCOPClause 8 of ITU-T Rec. Q.2130 applies with the following exception: The support of the AA-UNITDATA primitive is not mandatory.8.4.5 State Transition Table of SSCF for Supporting B-QSIG SignallingClause 9 of ITU-T Rec. Q.2130
40、 applies with the exceptions specified in sections 8.4.3 and 8.4.4 above.8.4.6 Boundary to Layer ManagementNo requirements have been identified.8.4.7 Applicability of SSCOP Parameters and Timers to B-QSIG SignallingThe values specified in table 4 of ITU-T Rec. Q.2130 are used as default parameters.H
41、owever, parameter and timer values at the B-QSIG-IPL shall be configurable, in order to be able to select aproper set of parameter and timer values depending on the use, condition, IPL link rate, round-trip delay, andreceiver resequencing buffer size. As a general guide, Timer_POLL should be set to
42、as large a value as possiblethat still maintains throughput efficiency and satisfies the average and maximum delivery of data.For the signalling channels at the Q reference point, no restrictions to operating at below 10 kbit/s applies.- 5 -8.4.8 PICS Proforma for SSCOP AND SSCOP-SSCFAnnex A applies
43、.8.4.9 SSCF for Semi-Permanent Connection (SPC) Control SignallingFunctions for the support of semi-permanent connections are outside the scope of this Standard.- 6 - 7 -Annex A(normative)Protocol Implementation Conformance Statement (PICS) proforma for B-QSIG SAALA.1 IntroductionA.1.1 Basic referen
44、ce documents for PICS proforma specificationsGeneral rules for the specification of PICS proforma are provided by ISO/IEC 9646-1. Detailed guidance for thespecification of PICS proforma is provided by ISO/IEC 9646-7; in particular the structure of a PICS proforma, thequestions to be asked, the synta
45、x and notation to be used and the semantics of the questions and expected answers.For a PICS proforma, specific acronyms and terms are used as defined in ISO/IEC 9646-1 or ISO/IEC 9646-7, e.g.: ICS Implementation Conformance Statement ICS proforma Implementation Conformance Statement proforma ICS (p
46、roforma) item A row in an ICS (proforma) table PICS Protocol ICS PICS proforma Protocol ICS proforma status (value) An allowed entry in the status column for an item in an ICS proforma table (support) answer An allowed entry in the support or supported values columns for an item in an ICSquestionA.1
47、.2 Copyright InformationUsers of this specification may freely reproduce the PICS proforma of this annex A so that it can be used for itsintended purpose and may further publish the completed PICS.A.1.3 Structure of this PICS proformaThis PICS proforma is subdivided into (sub-)clauses as follows: In
48、structions (A.2) Purpose of a PICS proforma (A.2.1) Instructions for completing the PICS proforma (A.2.2) Additional Information (A.2.3) Exception Information (A.2.4) Legend for the columns of the PICS proforma tables (A.2.5) Legend for further indications of the PICS proforma tables (A.2.6) Identif
49、ication of the implementation (A.3), including: Identification of the protocol for which this PICS applies (A.3.7) Global statement of conformance (A.4) SSCOP (A.5) SSCOP-SSCF B-QSIG Protocol Capabilities (A.6)- 8 -A.2 InstructionsA.2.1 Purpose of a PICS proformaTo evaluate conformance of a particular implementation, it is necessary to have a statement of which capabilitiesand options have been implemented for a given OSI specification. Such a statement is called an ImplementationConformance Statement (ICS).For protocol specifications, this statement is
