1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Q.2111 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (07/2001) SERIES Q: SWITCHING AND SIGNALLING Broadband ISDN Signalling ATM adaptation layer (SAAL) B-ISDN ATM adaptation layer Service specific connection oriented protocol in a multilink
2、and connectionless environment (SSCOPMCE) Amendment 1 ITU-T Recommendation Q.2111 Amendment 1 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR S
3、ERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Q.100Q.119 SPECIFICATIONS OF SIGNALLING SYSTEM No. 4 Q.120Q.139 SPECIFICATIONS OF SIGNALLING SYSTEM No. 5 Q.140Q.199 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 Q.250Q.309 SPECIFICATIONS OF SIGNALLING SYSTEM R1 Q.310Q.399 SPECIF
4、ICATIONS OF SIGNALLING SYSTEM R2 Q.400Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTERWORKI
5、NG WITH SATELLITE MOBILE SYSTEMS Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999 BROADBAND ISDN Q.2000Q.2999 General aspects Q.2000Q.2099 Signalli
6、ng ATM adaptation layer (SAAL) Q.2100Q.2199 Signalling network protocols Q.2200Q.2299 Common aspects of B-ISDN application protocols for access signalling and network signalling and interworking Q.2600Q.2699 B-ISDN application protocols for the network signalling Q.2700Q.2899 B-ISDN application prot
7、ocols for access signalling Q.2900Q.2999 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. Q.2111/Amd.1 (07/2001) i ITU-T Recommendation Q.2111 B-ISDN ATM adaptation layer Service specific connection oriented protocol in a multilink and connectionless environment (SS
8、COPMCE) AMENDMENT 1 Summary Recommendation Q.2111 provides assured data delivery between AAL connection endpoints in a multilink or a connectionless environment. This amendment has been prepared to allow operation over additional types of connectionless lower layer protocols and is designed to be co
9、mpatible with implementations conforming to that first edition of Recommendation Q.2111 (1999). The changes from Recommendation Q.2111 (1999) specify operation of SSCOPMCE over additional connectionless lower layers than the original publication of Q.2111 (1999). Specifically, the additional connect
10、ionless environments are: IP, as modified by Differentiated Services in IETF RFC 2474; and Ethernet, as defined in ISO/IEC 8802.3. This amendment supersedes the Implementors Guide published in December 2000. Source Amendment 1 to ITU-T Recommendation Q.2111 was prepared by ITU-T Study Group 11 (2001
11、-2004) and approved under the WTSA Resolution 1 procedure on 13 July 2001. ii ITU-T Rec. Q.2111/Amd.1 (07/2001) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-
12、T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four ye
13、ars, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the nec
14、essary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the
15、 possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of
16、 the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest infor
17、mation and are therefore strongly urged to consult the TSB patent database. ITU 2002 All rights reserved. No part 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 ITU. ITU
18、-T Rec. Q.2111/Amd.1 (07/2001) iii CONTENTS Page 1) Clause 2. 1 2) Clause 4. 2 3) Clause 5.3 4 4) Clause 7.3.3. 4 5) Clause C.1. 4 6) Annexes D and E 5 7) Appendix I 22 ITU-T Rec. Q.2111/Amd.1 (07/2001) 1 ITU-T Recommendation Q.2111 B-ISDN ATM adaptation layer Service specific connection oriented pr
19、otocol in a multilink and connectionless environment (SSCOPMCE) AMENDMENT 1 Replace clauses 2 and C.1 and modify clauses 5 and 7.3.3 with the text presented in this Amendment. The differences from ITU-T Recommendation Q.2111 (1999) for these sections are marked to emphasize the compatibility of this
20、 Amendment with the original publication of this Recommendation. Enhance clause 4 with the additional abbreviations presented in this Amendment. Add new Annexes D (Convergence function for SSCOPMCE above IP or UDP with Differentiated Services) and E (Convergence Function for SSCOPMCE Above Ethernet)
21、 Replace Appendix I by the Appendix I provided in this amendment. The additional and modified text follows. 1) Clause 2 2 References 2.1 Normative references The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of th
22、is Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and othe
23、r references listed below. A list of the currently valid ITU-T Recommendations is regularly published. 1 ITU-T X.200 (1994), Information technology Open Systems Interconnection Basic Reference Model: The basic model. 2 ITU-T X.210 (1993), Information technology Open Systems Interconnection Basic Ref
24、erence Model: Conventions for the definition of OSI services. 3 ITU-T I.150 (1999), B-ISDN asynchronous transfer mode functional characteristics. 4 ITU-T I.361 (1999), B-ISDN ATM layer specification. 5 ITU-T I.363.5 (1996), B-ISDN ATM Adaptation Layer specification: Type 5 (AAL). 6 ITU-T Q.2110 (199
25、4), B-ISDN ATM adaptation layer Service specific connection oriented protocol (SSCOP). 7 IETF RFC 768 (1980), User Datagram Protocol. 8 IETF RFC 791 (1981), Internet Protocol. 9 IETF RFC 792 (1981), Internet Control Message Protocol. 10 IETF RFC 1122 (1989), Requirements for Internet Hosts Communica
26、tion Layers. 10 bis IETF RFC 2474 (1998), Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers. 2 ITU-T Rec. Q.2111/Amd.1 (07/2001) 10 ter ISO/IEC 8802-3:2000, Information technology Telecommunications and information exchange between systems Local metropolitan are
27、a networks Specific requirements Part 3: Carrier sense multiple access with collision detection CSMA/CD access method and physical layer specifications. 2.2 Bibliography The documents listed in this clause provide informative background information for the reader and are not normative within this Re
28、commendation. 11 ITU-T Q.2100 (1994), B-ISDN signalling ATM adaptation layer (SAAL) Overview description. 12 ITU-T Q.2130 (1994), B-ISDN signalling ATM adaptation layer Service specific coordination function for support of signalling at the user-to-network interface (SSCF at UNI). 13 ITU-T Q.2140 (1
29、995), B-ISDN ATM adaptation layer Service specific coordination function for signalling at the network node interface (SSCF at NNI). 14 ITU-T I.365.2 (1995), B-ISDN ATM adaptation layer sublayers: Service-specific coordination function to provide the connection-oriented network service. 15 ITU-T I.3
30、65.3 (1995), B-ISDN ATM adaptation layer sublayers: Service-specific coordination function to provide the connection-oriented transport service. 16 ITU-T I.363.2 (2000), B-ISDN ATM Adaptation Layer specification: Type 2 AAL. 17 ITU-T I.366.1 (1998), Segmentation and Reassembly Service Specific Conve
31、rgence Sublayer for the AAL Type 2. 18 ITU-T Q.2119 (1996), B-ISDN ATM adaptation layer Convergence function for SSCOP above the frame relay core service. 19 IETF RFC 2475 (1998), An Architecture for Differentiated Services. 20 ISO/IEC 8802-2:1998, Information technology Telecommunications and infor
32、mation exchange between systems Local and metropolitan area networks Specific requirements Part 2: Logical link control. 21 ISO/IEC 15802-3:1998, Information technology Telecommunications and information exchange between systems Local and metropolitan area networks Common specifications Part 3: Medi
33、um Access Control (MAC) Bridges. 22 IEEE 802.1Q (1998), IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks. 2) Clause 4 4 Abbreviations Add the following list of abbreviations, alphabetically, to those already contained in clause 4: CFI Canonical Format Indi
34、cator CPCS-CI Common Part Convergence Sublayer Congestion Indication CPCS-LP Common Part Convergence Sublayer Loss Priority CPCS-RS Common Part Convergence Sublayer Reception Status CPCS-UU Common Part Convergence Sublayer User-to-User Indication CPI Common Part Indicator ITU-T Rec. Q.2111/Amd.1 (07
35、/2001) 3 CRC Cyclic Redundancy Check CSMA/CD Carrier Sense Multiple Access with Collision Detection CU Currently Unused DF Dont Fragment DS Differentiated Services DSCP Differentiated Services Codepoint FCS Frame Check Sequence FO Fragment Offset ICMP Internet Control Message Protocol ID Identificat
36、ion IDU Interface Data Unit IEC International Electrotechnical Commission IEEE Institute of Electrical and Electronics Engineers IETF Internet Engineering Task Force IHL Internet Header Length ISO International Organization for Standardization LAN Local Area Network LLC Logical Link Control LSRR Loo
37、se Source and Record Route MAC Medium Access Control MF More Fragments NCFI Non-Canonical Format Indicator PROT Protocol PVID Port Virtual LAN identifier RFC Request For Comment RIF Routing Information Field RR Record Route SFD Start Frame Delimiter SNAP Sub-Network Access Protocol Identifier SSRR S
38、trict Source and Record Route TCI Tag Control Information TCP Transmission Control Protocol TL Total Length TOS Type Of Service TTL Time To Live VID Virtual LAN Identifier VLAN Virtual LAN 4 ITU-T Rec. Q.2111/Amd.1 (07/2001) 3) Clause 5.3 5 General Modify the paragraph immediately following Figure 2
39、 as follows: A representation of SSCOPMCE operating in a connectionless environment is shown in Figure 3. In this mode the SSCOPMCE entity operates more like a transport layer protocol and is clearly outside the scope of an AAL. Through the lower Service Access Point (SAP), a connectionless service,
40、 such as IP (IETF RFC 791 8) or UDP (IETF RFC 768 7), delivers SSCOPMCE PDU payload fragments for delivery to the user of the SSCOPMCE entity and accepts SSCOPMCE PDUs for transfer to the peer user. Annex C describes the mapping of primitives across this SAP with IP and UDP. Annexes C and D describe
41、 the mapping of primitives across this SAP with IP and UDP; Annex C covers legacy IP networks while Annex D covers IP networks that support differentiated services. Annex E covers operation over an Ethernet databus. 4) Clause 7.3.3 Modify as follows: 7.3.3 Connectionless environment The signals defi
42、ned in this subclause were originally defined for the ATM adaptation layer environment; they bear little resemblance to any known connectionless environment. For such environments a convergence function is needed (this is to a large extent a modelling artifact). Such a functions for IP or UDP based
43、communications isare defined in Annexes C and D to this recommendation. 5) Clause C.1 Modify as follows: C.1 General description The convergence function for SSCOPMCE above IP provides for the possibility to deploy SSCOPMCE on top of the connectionless service provided by IP. The IP service utilises
44、 protocol defined in IETF RFCs 791 8 and 1122 10. Alternatively, UDP service, as defined in IETF RFC 768 7, may be used. Both alternatives are discussed in this annex. All protocol stacks that include SSCOPMCE can, therefore, also be used in an IP-based networks. A particular application of this arr
45、angement is a protocol stack for SS No. 7 signalling. NOTE The convergence function of this annex, being based upon IETF RFC 791 8, is designed specifically for operation with IPv4. If use is desired of an application, e.g. the “Differentiated Services“ defined in IETF RFC 2475 19, which IETF define
46、d “DIFFSERV“, that is not compatible with IETF RFC 791 8, then this annex is not applicable; for the application of “Differentiated Services“ see Annex D.; for the application of “Differentiated Services“ see Annex D. ITU-T Rec. Q.2111/Amd.1 (07/2001) 5 6) Annexes D and E Add new Annexes D and E: AN
47、NEX D Convergence function for SSCOPMCE above IP or UDP with Differentiated Services D.1 General description The convergence function for SSCOPMCE above IP provides for the possibility to deploy SSCOPMCE on top of the connectionless service provided by IP. The IP service utilizes protocol defined in
48、 IETF RFCs 791 8 and 1122 10. In addition, the Differentiated Services Field is defined in IETF RFC 2474 10 bis. Alternatively, UDP service, as defined in IETF RFC 768 7, may be used. Both alternatives are discussed in this annex. NOTE The architecture of the differentiated service is described in I
49、ETF RFC 2475 19. All protocol stacks that include SSCOPMCE can, therefore, also be used in IP-based networks that deploy the differentiated service. A particular application of this arrangement is a protocol stack for SS No. 7 signalling. D.2 Functions of the convergence function The purpose of the convergence function is to map information between SSCOPMCE and IP (or UDP) PDUs. Appropriate headers must be created as is customa
