1、 STD.ITU-T RECMN X-215 AMD 2-ENGL 1397 = 4862591 Ob50840 881 = INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUN 1 CATI ON STANDARDIZATION SECTOR OF ITU X.215 Amendment 2 (1 2/97) SERIES X: DATA NETWORKS AND OPEN SYSTEM COM M U N I CATI O N Open System Interconnection - Service definitions Info
2、rmation technology - Open Systems Interconnection - Session service definition Amendment 2: Nested connections functional unit ITU-T Recommendation X.215 - Amendment 2 (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS Se
3、rvices and facilities Interfaces X.20-X.49 Transmission, signalling and switching X.50-X. 89 Network aspects X.90-X.149 Maintenance X. 150-X. 179 Administrative arrangements X. 180-X. 199 X. 1 -X. 19 OPEN SYSTEM INTERCONNECTION Model and notation X .200-X . 209 Service defitions X.210-X.219 Connecti
4、on-mode protocol specifications X.220-X.229 Connectionless-mode protocol specifications X.230-X.239 PICS profonnas X.240-X.259 Protocol Identification X.260-X.269 Security Protocols X.270-X.279 Layer Managed Objects X.280-X.289 Conformance testing X.290-X.299 INTERWORKING BETWEEN NETWORKS General X.
5、300-X.349 Satellite data transmission systems X.350-X.399 MESSAGE HANDLING SYSTEMS X.400-X .499 DIRECTORY X.500-X.599 OS1 NETWORKING AND SYSTEM ASPECTS Networking X .600-X. 629 Efficiency X.630-X.639 Quality of service X.640-X. 649 Naming, Addressing and Registration X.650-X.679 Abstract Syntax Nota
6、tion One (ASN. i) X.680-X.699 OS1 MANAGEMENT Systems Management framework and architecture Management Communication Service and Protocol X.700-X.709 X.7 1 O-X.7 1 9 X.720-X.729 X.730-X.799 Structure of Management Information Management functions and ODMA functions SECURITY X. 800-X.849 OS1 APPLICATI
7、ONS Commitment, Concurrency and Recovery X.850-X.859 Transaction processing X.860-X.879 Remote operations X.880-X.899 OPEN DISTRIBUTED PROCESSING X.900-X.999 For further details, please refer to TU-T List of Recommendations. INTERNATIONAL STANDARD 8326 ITU-T RECOMMENDATION X.215 INFORMATION TECHNOLO
8、GY - OPEN SYSTEMS INTERCONNECTION - SESSION SERVICE DEFINITION AMENDMENT 2 Nested connections functional unit Summary The Session service definition defined in ITU-T Rec. X.215 I ISO/IEC 8326 is enhanced to define an optional functional unit which permits additional, independent, nested session conn
9、ections within an existing session connection. This enhancement will support the reusability of existing application layer standards (each making full, and possibly incompatible, use of the session synchronization services) as components of new application layer standards Source The ITU-T Recommenda
10、tion X.215, Amendment 2 was approved on the 12th of December 1997. The identical text is also published as ISO/IEC International Standard 8326, Amendment 2. ITU-T Rec. X.215 (1995)/Amd. 2 (1997 E) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the
11、field of telecommuni- cations. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The IT-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide b
12、asis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the p
13、rocedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both
14、 a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recornmendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concernin
15、g the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by pa
16、tents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1998 All rights reserved. No part of this publication may be reproduced or
17、utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 LTU-T Rec. X.215 (1995)/Amd. 2 (1997 E) . STD-ITU-T RECMN X-215 AMD 2-ENGL 1997 4862593 0650844 427 CONTENTS Page New subclauses 3.3.12 and 3.3.13 . 1
18、New subclause 7.7 1 Clause 8 Subclause 8.3 . New subclause 9.1.1 5 . Subclause 11.3 . Subclause 12.1.1 Subclause 12.1.2 Subclauses 12.1.2.2, 12.1.2.3 and 12.1.2.4 Subclause 12.1.2.7 . . Subclause 13.1 1.2 Subclause 14.3.2 Subclause 15.2 . Subclause A.l . ITU-T Rec . X.215 (1995)/Amd . 2 (1997 E) 2 2
19、 2 3 3 ? 3 3 3 3 . 111 STD-ITU-T RECMN X.215 AND 2-ENGL 1777 = 4862571 0650845 363 = ISO/IEC 8326 : 1996/Amd.2 : 1998 (E) INTERNATIONAL STANDARD ITU-T RECOMMENDATION INFORMATION TECHNOLOGY - OPEN SYSTEMS INTERCONNECTION - SESSION SERVICE DEFINITION AMENDMENT 2 Nested connections functional unit 1) N
20、ew subclauses 3.3.12 and 3.3.13 Addafter3.3.11: 3.3.12 connection. nested session connection: A session connection which is logically embedded within an existing session 3.3.13 machine, session protocol data units for a nested session connection are discarded. nested session exception: A condition w
21、hich occurs if, as a result of discard by an enclosing session protocol 2) New subclause 7.7 Add a new subclause 7.7: 7.7 Nested session connections A pair of session service users may communicate using a single session connection, or may choose to establish additional session connections nested wit
22、hin the outermost connection (or within each other) to any depth. The provisions of this Recommendation I International Standard apply independently to each such connection, except where stated otherwise, with each connection independently determining at connection establishment time the session fun
23、ctional units that are available on that connection. The initiator of an outer-level session connection can initiate nested connections provided use of the nested connection functional unit has been negotiated on the immediately enclosing session connection, and provided there are no more than 126 n
24、ested session connections currently established (by the initiator) on this outer-level connection. The acceptor of an outer-level session connection can initiate nested connections provided use of the nested connection functional unit has been negotiated on the immediately enclosing session connecti
25、on, and provided there are no more than 127 nested session connections currently established (by the acceptor) on this outer-level connection. ITU-T Rec. X.215 (1995)/Amd. 2 (1997 E) 1 STDmITU-T RECNN X.215 AND 2-ENGL 1777 4862571 Ob50846 2TT ISO/IEC 8326 : 1996/Arnd.2 : 1998 (E) Interactions betwee
26、n connections that are nested within an outermost connection are as follows: a) b) Ail such connections are carried on a single transport connection, and the sequencing rules of 11.3 apply no matter what connection the primitives are issued on. Services provided on connections that are nested (at an
27、y level) within a common parent, but are not nested within each other, never disrupt each others services. Flow on such connections can, however, be blocked by flow control exercised on other such connections. Services provided on connections that contain nested connections can disrupt services on t
28、he nested connections, and may cause exception reports or aborting on those connections. Disrupting services on outer connections are not blocked by flow control exercised on an inner nested connection. All services (including connection establishment) for a nested connection can be invoked only if
29、all enclosing connections permit the invocation of the data transfer service. If an outer connection is terminated (by orderly release or by an abort), any nested connection that has not yet been terminated receives a provider abort. NOTE - The above rules give maximum choice to designers, providing
30、 a clear differentiation between use of wholly separate session connections (no sequencing), use of parallel nested connections (sequenced, potentially mutually blocking, but not disruptive), use of nested connections (sequenced, the outer is not blocked but can be disruptive, and retains control of
31、 all activity). c) d) e) 3) Clause 8 Add ujier the)rst paragraph. The Session Connection service can also be used to establish nested session connections within an already established session connection. 4) Subclause 8.3 Add at the end of this subclause: If a session connection is released, all nest
32、ed connections are released by the provider-initiated abort service. 5) New subclause 9.1.15 Add afier 9.1.14: 9.1.15 Nested connections functional unit The nested connections functional unit supports the establishment of nested session connections. If this functional unit is not selected the connec
33、tion establishment service cannot be used on an existing connection. 4 6) Subclause 11.3 Add at the end of this subclause: The above sequencing rules apply to all primitives issued on any connection that is nested within the same outermost session connection, even if two such primitives occur on dif
34、ferent connections in the set. 7) Subclause 12.1.1 Add at the end of this subclause: This service also allows the establishment of nested session connections which may have different session connection parameters from those of the parent connection. 8) Subclause 12.1.2 In Table 9, change the M for C
35、alling Session Address, Called Session Address, and Responding Session Address to C. 2 ITU-T Rec. X.215 (1995)/Arnd. 2 (1997 E) STD=ITU-T RECMN X.215 AND 2-ENGL II997 4862591 Ob50847 II36 ISO/IEC 8326 : 1996lAmd.2 : 1998 (E) 9) Subclauses 12.1.2.2,12.1.2.3 and 12.1.2.4 Add at the end of each of 12.1
36、.2.2, 12.1.2.3 and 12.1.2.4: The parameter is mandatory except when the connect service is used to establish a nested session connection, when it shall be absent. 10) Subclause 12.1.2.7 Add a new item n) to this subclause: n) nested connections functional unit. 11) Subclause 13.11.2 Add a new item c
37、) to this subclause: c) disrupted service (this only occurs on a nested connection). 12) Subclause 14.3.2 Add new items b) and c) to this subclause and rename existing b) through d) as d) through f): b) c) containing connection released (this only occurs on a nested connection); disrupted service (t
38、his only occurs on a nested connection); 13) Subclause 15.2 Add at the end of the sentence in this subclause: . except that services on a nested session connection can only be invoked if all enclosing connections permit the invocation of the data transfer service. 14) Subclause A.l Add at the end of
39、 this subclause: A request or response primitive on a nested session connection (including an S-CONNECT request or response establishing such a connection) can occur only if the following apply: a) b) it is permitted by the state table for that connection; and the state table for all enclosing conne
40、ctions permit an SDTreq event. An indication or confirm primitive on a nested connection (including an S-CONNECT indication or confirm establishing such a connection) will occur only if the following apply: a) b) it is permitted by the state table for that connection; and the state table for all enc
41、losing connections permit an SDTind event. ITU-T Rec. X.215 (1995)lArnd. 2 (1997 E) 3 I ieries A ;cries B Series C Series D series E Series F Series G Series H Series I Series J Series K Series L Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series V Series X Serie
42、s Y Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff principles Overall network operation, telephone service, service operation and human factors Non-telephone tel
43、ecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound programme and other multimedia signals Protection against interference Construction, installation and protecti
44、on of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: international sound programme and television transmission circuits Specifications of measuring equipment Teleph
45、one transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Global information infrastructure Programming languages Printed in Switzerland Geneva, 1998
