1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU INTEGRATED SERVICES DIGITAL NETWORK (ISDN) OVERALL NETWORK ASPECTS AND FUNCTIONS 1.365.3 (1 1 /95) B-ISDN ATM ADAPTATION LAYER SUBLAYERS: SERVICE SPECIFIC COORDINATION FUNCTION TO PROVIDE SERVICE THE CONNECTI
2、ON-ORIENTED TRANSPORT ITU-T Recommendation 1.365.3 (Previously “CCIlT Recommendation“) ITU-T RECMN*I.365- *3 95 4862591 0617769 b54 = FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The IW-T is responsible for stu
3、dying technical, operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study
4、 Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the IT-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). .ITU-T Recommendation 1.365.3 was prepared by ITU-T Study Group 13 (1993-1996
5、) and was approved under the WTSC Resolution No. 1 procedure on the 2nd of November 1995. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1996 All rights reserved. No par
6、t of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. ITU-T RECMN*I.365. 83 75 H 4862571 Ob17770 376 1 2 3 4 5 6 7 8 9 10 11 CONTENTS Scope Normative References Defi
7、nitions Abbreviations . Conventions General Description . Services provided by the SSCF-COTS Functions of the SSCF-COTS Elements for layer-to-layer communication . 9.1 Primitives between SSCF-COTS and SCF . 9.1.2 Parameter definition Signals between SSCF-COTS and SSCF-COTS Layer Management 9.2.1 Sig
8、nal definition 9.2.2 Parameter definition 9.2.3 States at the boundary between SSCF-COTS and Layer Management Signals between SSCF-COTS and SSCOP 9.3.2 Parameter definition 9.4 State transition diagram for sequences of signals at the layer boundaries of SSCF-COTS Protocol elements for peer-to-peer c
9、ommunication . 9.1.1 Definition of primitives . 9.2 9.3 9.3.1 Definition of signals 10.1 10.2 10.3 10.4 10.5 10.6 SSCF-COTS PDUS . 10.1.1 SSCF-COTS PDUs utilizing the unassured data transfer . 10.1.2 SSCF-COTS PDUs utilizing the assured data transfer . 10.1.3 SSCF-COTS PDUs utilizing data transfer c
10、apabilities in SSCOP connection control services SSCF-COTS PDU formats . 10.2.1 Coding conventions 10.2.2 PDU length . SSCF-COTS PDU fields . SSCF-COTS state variables 10.4.1 Transmitter state variables 10.4.2 Receiver state variables . 10.4.3 Common state variables SSCF-COTS timers SSCF-COTS protoc
11、ol parameter Specification of the SSCF-COTS . 11.1 Overview 11.1.1 Idle 11.1.2 Establishment and release . 11.1.3 Data transfer 11.2 State transition table 11.3 SDL diagrams . Recommendation 1.365.3 (11/95) Page 1 1 2 2 3 3 4 6 7 7 7 8 9 9 9 10 10 10 10 11 13 14 14 15 15 15 15 17 17 19 19 20 20 20 2
12、0 20 20 20 21 22 22 22 1 ITU-T RECMN*I.365 . *3 95 = 4862591 Ob37773 202 Annex A . Management error indications Annex B . Default values for SSCOP parameters and timers . Annex C - Expedited Data Transfer service . Protocol elements for peer-to-peer communication SSCF-COTS PDU formats SSCF-COTS PDU
13、parameter fields Additional states of the SSCF-COTS protocol entity . Additional SSCF-COTS state variables SSCF-COTS timers . Specification ofthe Expedited Data service procedure Annex D - Quality of Service parameter negotiation . Parameters and their negotiation for the “Empty” QOS set Parameters
14、and their negotiation for the “Standard CONS QOS set Negotiation of QOS Parameters C.l C . 1.1 C . 1.2 C . 1.3 C.1.4 C.1.5 C . 1.6 SSCF-COTS PDUS . C.2 D.l D.2 D.2.1 D.2.2 QOS Parameters at the SSCF-COTS/SSCF-COTS user boundary . Annex E - Supplementary specification for the SCF (Recommendation 4.92
15、3) . Adaptation of the primitive names to the Transport Service E.l.l Introduction . E.1.2 Abbreviations E.1.3 Interpretation . E.1.4 X.214 type of service E.1.5 Summary of the Sub-N-Service primitives at the N(c)C endpoint . E . 1.6 Deletion of the Reset service E.1.7 State transition table E.2 Sel
16、ection of predicates Mapping of the C-plane Sub-N-Service . E.l E.3 Appendix I - T(u)-primitive sequences at the UNI for connection establishment and release within the U-plane and their relationship to AA-signals and SSCOP PDU sequences . Appendix II - Further considerations for the default values
17、for the SSCOP parameters and timers II.1 Definitions II.2 Goal II.3 Frame size . II.4 Qualitative Analysis II.4.1 Assumptions LI.4.2 Timing in the absence of eKors . II.4.3 Timing for single corrupted data frame correction . II.4.4 Timing for single corrupted POLL or STAT PDU . II.4.5 Multiple error
18、s II.5 Conclusion 42 43 44 44 44 44 45 46 46 47 48 56 56 56 57 57 59 60 60 60 60 60 60 61 62 62 62 64 75 75 75 76 76 76 76 77 78 78 78 11 Recommendation 1.365.3 (1U95) ITU-T RECMN*I.365. *3 95 rn 4862593 Ob17772 149 m SUMMARY The ATM Adaptation Layer (AAL) is defined to enhance the services provided
19、 by the ATM layer to support the functions required by the next higher layer. One particular type of service supported by the AAL is the Connection Oriented Transport Service (COTS). The AAL for COTS comprises functions necessary to support COTS data communications between peer entities in the user
20、plane. The AAL for COTS consists of a Segmentation And Reassembly (SAR) function, and a Convergence Sublayer which is specified as two sublayers: a Common Part Convergence Sublayer (CES) and a Service Specific Convergence Sublayer (SSCS). The CPCS is defined in clause 6fl.363 and is used as the unde
21、rlying protocol for the service specific part for COTS. The SSCS is functionally divided into two parts: the Service Specific Connection Oriented Protocol (SSCOP), which provides an assured data transfer service, and the Service Specific Coordination Function (SSCF). The SSCOP is defined in Recommen
22、dation 4.21 10 4 and is suitable for use by various SSCFs. This Recommendation specifies the SSCF for COTS. This Recommendation describes for the SSCF-COTS the mapping of primitives from the Synchronization and Coordination Function (SCF) (defined in Recommendation 4.923 3) to signais of the SSCOP a
23、nd vice versa. It also specifies the exchange of signals between Layer Management and the SSCF-COTS. KEYWORDS Asynchronous Transfer Mode (ATM), ATM Adaptation Layer (AAL), Broadband Integrated Services Digital Network (B-ISDN), Connection Oriented Transport Service (COTS), Service Specific Coordinat
24、ion Function (SSCF). . Recommendation 1.365.3 (1Y95) 111 ITU-T RECMN*I-365. U3 75 = 48h2593 Oh37773 085 ITU-T RECNN*I.365. 83 95 4862571 Ob1777Y TI1 = Recommendation 1.365.3 B-ISDN ATM ADAPTATION LAYER SUBLAYERS: SERVICE SPECIFIC COORDINATION FUNCTION TO PROVIDE THE CONNECTION ORIENTED-TRANSPORT SER
25、VICE (Geneva, 1995) 1 Scope This Recommendation specifies a function that is part of the ATM Adaptation Layer to support the OS1 Connection Oriented Transport Service (COTS) within the B-ISDN. This function is used to map the service of the Service Specific Connection Oriented Protocol (SSCOP) of th
26、e AAL to the requirements of a Transport Service user as defined in Recommendation X.214 7. This function is called Service Specific Coordination Function to provide COTS (S SCF-COTS). This Recommendation covers the specification of the SSCF identified in the complete AAL structure for connection or
27、iented data communications defined in Recommendation 1.363 2 and describes the relationship to the protocol entity providing the Transport Service defined in Recommendation X.214 7, the Service Specific Connection Oriented Protocol defined in Recommendation Q.2110 4 and Layer Management. This Recomm
28、endation is applicable to equipment to be attached to a B-ISDN User Network Interface (UNI) or B-ISDN Network Node Interface (hN) when the OS1 Connection Oriented Transport Service is to be supported. 2 Normative References The following Recommendations and other references contain provisions which,
29、 through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of
30、applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITLJ-T Recommendations is regularly published. IT-T Recommendation 1.361 (1993). B-ISDN ATM layer specification. ITLJ-T Recommendation 1.363 (1993), B-ISDNATM Adaptation Layer (AA
31、L) specification. IT-T Recommendation Q.923 (1995), Specijication of u synchronization und coordination function for the provision of the OSI connection-mode network service in an ISDN environment. ITU-T Recommendation 4.2 1 10 (1994), B-ISDN ATM Adaptation Layer-Service Specific Connection Oriented
32、 Protocol (SSCOP). ITU-T Recommendation X.200 (1 994), Information technology - Open Systems Interconnection - Basic reference model: The basic model. IT-T Recommendation X.210 (1993), Information technology - Open Systems Interconnection - Basic reference model: conventions for the definition of OS
33、I services. ITU-T Recommendation X.2 14 (1993), Information technology - Open Systems Interconnection - Transport service definition. ITU-T Recommendation X.223 (1993), Use of X.25 to provide the OSI connection-mode network service for ITU-T applications. 1 Recommendation 1.365.3 (11/95) ITU-T RECMN
34、*I*3b5- *3 95 m 48b2591 Ob17775 958 m ITU-T Recommendation 4.295 1 (1999, Stage 3 description for number identijcation supplementary services using D-ISDN Digital Subscriber Signalling System No. 2 - Basic Call - Clause 8 - Sub-addressing (SUB). ITU-T Recommendation Q.2957 (1995). Stage 3 descriptio
35、n for additional information transfer supplementary services using B-ISDN Digital Subscriber Signalling System No. 2 (DSS 2) - Basic Call - Ciause 1 - User-to- User Signalling (UUS). CCITT Recommendation X.650 (1992), Open Systems Interconnection (OSI) - Reference model for naming and addressing. IS
36、O/IEC ISP 10609-3: 1992, Informution technology - International Standardized Profiles TB, TC, TD and TE - Connection-mode Transport Service over connection-mode Network Service - Part 3: Subnetwork-type independent requirements for Group TD. Definitions This Recommendation is based upon the concepts
37、 developed in Recommendation X.200 5 and makes use of the following terms defined in that Recommendation: a) connection oriented; b) expedited data transfer; c) Transport Layer; d) Transport Service; e) Transport Service Access Point. This Recommendation is based upon the concepts developed in Recom
38、mendation 1.363 2 and makes use of the following terms defined in that Recommendation: a) b) Common Part Convergence Sublayer; c) Segmentation and Reassembly Sublayer; d) Service Specific Convergence Sublayer. Asynchronous Transfer Mode Adaptation Layer; Furthermore, this Recommendation is based upo
39、n the concepts developed in Recommendation Q.2110 4 and makes use of the following terms defined in that Recommendation: a) Service Specific Coordination Function; b) Service Specific Connection Oriented Protocol. 4 Abbreviations For the purposes of this Recommendation, the following abbreviations a
40、re used. AAL ATM Adaptation Layer ATM Asynchronous Transfer Mode cc COTS Connection Oriented Transport Service CP Common Part CPCS Common Part Convergence Sublayer CR DATA (normal) Data (PDU) DR ED Expedited Data (PDU) EDAK Expedited Data Acknowledgement (PDU) PCI Protocol Control Information Connec
41、tion Establishment - Confirmation (PDU) Connection Establishment - Request (PDU) Connection Release - Disconnect (PDU) 2 Recommendation 1.365.3 (1YgS) ITU-T RECMN*I-365* *3 75 4862573 0637776 894 = PDU Protocol Data Unit QOS Quality of Service SAAL AAL for Signalling SAP Service Access Point SAR Seg
42、mentation And Reassembly SCF Synchronization and Coordination Function SDL SDU SSCF sscs SSCOP SSCOP-uu TS TSAP T-SDU Specification and Description Language Service Data Unit Service Specific Coordination Function Service Specific Convergence Sublayer Service Specific Connection Oriented Protocol SS
43、COP User-to-User parameter (OSI) Transport Service (OSI) Transport Service Access Point Transport Service Data Unit 5 Conventions The primitives at the AAL type 5 SAP are conventionally called “AAL-primitives”. However, as defined in the General Descriptions (see 6) and shown in Figure 2, the SCF as
44、 defined in Recommendation 4.923 3 is the immediate user of this AAL type 5 and the primitives there are defined in terms of T(u)-primitives, this Recommendation defines the primitives across the AAL type 5 SAP also as T(u)-primitives. 6 General Description The Service Specific Coordination Function
45、 providing the Connection Oriented Transport Service (SSCF-COTS) resides in the Service Specific Convergence Sublayer (SSCS) of the ATM Adaptation Layer (AAL). It deploys the services provided by the Service Specific Connection Oriented Protocol (SSCOP) defined in Recommendation Q.2110 141. SSCOP al
46、so resides in the SSCS. Figure 1 illustrates the structure of the AAL. The SSCF-COTS provides for the service that is requested by the Synchronization and Coordination Function (SCF) defined in Recommendation Q.923 3. This SCF in turn provides the Connection Oriented Transport Service (COTS) as defi
47、ned in Recommendation X.214 7. The SCF also utilizes the signalling capabilities defined for the C-plane. Figure 2A illustrates the B-ISDN structure of the U-plane and C-plane for switched ATM connections. For permanent ATM connections, the SCF interfaces with the M-plane instead of with the C-plane
48、; this situation is shown in Figure 2B. Supplementary specifications for the SCF as required by Recommendation 4.923 3 are defined in Annex E. The definition of the SSCF-COTS takes into consideration the principles and terminology of Recom- mendations X.200 5 and X.210 6, the reference model and the
49、 service conventions for Open Systems Interconnection (OSI). This Recommendation specifies: the interactions between the SSCF-COTS and the SCF sublayer; the interactions between the SSCF-COTS and the SSCOP sublayer; the interactions between the SSCF-COTS and the AAL management; and the peer-to-peer protocol that enhances the SSCOP service to provide the Connection Oriented Transport Service (COTS). Recommendation 1.365.3 (11/95) 3 ITU-T RECNN*I.365= X3 95 4b259L b37777 720 = a U I 1 I Service Specific Coordination Functim Signals I SeMce Specific C
