1、INTERNATIONAL TELECOMMUN ICATION UN ION ITU-T TELECOMMUN ICATION STANDARDIZATION SECTOR OF ITU . X.226 Amendment 1 (08197) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMM UN I CATI ON Open System Interconnection - Connection-mode protocol specifications Information technology - Open Systems Interconnec
2、tion - Connection-oriented presentation pro tocol : Pro tocol specification Amendment 1 : Efficiency enhancements ITU-T Recommendation X.226 - Amendment I (Previously CCITT Recommendation) ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION PUBLIC DATA NETWORKS X. 1-X. 199 Ser
3、vices and facilities Interfaces Transmission, signalling and switching Network aspects Maintenance Administrative arrangements OPEN SYSTEM INTERCONNECTION Model and notation II Service definitions . II Connection-mode protocol specifications X.l-X.19 X.20-X.49 X.50-X . 89 X.90-X. 149 X. 150-X. 179 X
4、.180-X.199 X.200-X.299 X.200-X.209 X.210-X.219 X.220-X.229 Connectionless-mode protocol specifications PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing INTERWORKING BETWEEN NETWORKS General Satellite data transmission systems MESSAGE HANDLING SYSTEM
5、S DIRECTORY OS1 NETWORKING AND SYSTEM ASPECTS Networking Efficiency Naming, Addressing and Registration Abstract Syntax Notation One (ASN.l) OS1 MANAGEMENT Systems Management framework and architecture Management Communication Service and Protocol Structure of Management Information Management funct
6、ions SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING X.230-X.239 X.240-X.259 X.260-X.269 X.270-X.279 X.280-X.289 X.290-X.299 X.300-X. 399 X.300-X.349 X.350-X.399 X.400-X.499 X.500-X.599 X.600-X.699 X.600-X.629 X.630-
7、X.649 X.650-X.679 X.680-X.699 X.700-X.799 X.700-X.709 X.7 1 O-X.7 1 9 X.720-X.729 X.730-X.799 X.800-X. 849 X.850-X. 899 X.850-X.859 X.860-X.879 X.880-X.899 X.900-X.999 For further details, please refer to ITU-T List of Recommendations. STD.ITU-T RECNN X.22b AND 1-ENGL I777 m 48b257L Cibi35Lt5 474 IN
8、TERNATIONAL STANDARD 8823-1 ITU-T RECOMMENDATION X.226 INFORMATION TECHNOLOGY - OPEN SYSTEMS INTERCONNECTION - CONNECTION-ORIENTED PRESENTATION PROTOCOL: PROTOCOL SPECIFICATION AMENDMENT 1 Efficiency enhancements Summary This amendment defines several efficiency options. The fast associate mechanism
9、 defines the construction of the User Summary parameter of the S-CONNECT primitives from the semantics of the presentation CP-PPDU fields. This amendment describes a protocol option which defines an alternative header encoding for the user-data of most presentation primitives when this contains only
10、 one presentation data value. When used in combination with the session short-encoding option, it minimizes the overhead for this common case, without loss of overall function, as the short encoding can be freely mixed with the non-compressed encodings. The nominated context presentation protocol op
11、tion allows for the “simple-encoding” CHOICE for the presentation user-data to be used for one of the presentation contexts of the Defined Context Set (DCS) even when there are many elements in the DCS. This allows a significant reduction in the presentation Protocol Control Information (PCI) overhe
12、ad for any application that sends most of its data in the same presentation context without any loss of functionality. In another efficiency option, the use of the Packed Encoding Rules (PER) for the presentation protocol allows the full range of values for the presentation protocol to be conveyed w
13、ith a smaller overhead in terms of the bits to be sent. Source The ITU-T Recommendation X.226, Amendment 1 was approved on the 9th of August 1997. The identical text is also published as ISOIIEC International Standard 8823- 1. ITU-T Rec. X.226 (1994)Amd.l (1997 E) i FOREWORD ITU (International Telec
14、ommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The IT Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on t
15、hem 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 Groups which, in their turn, produce Recommendations on these topics. The approva
16、l of Recommendations by the Members of the ITU-T is covered by the procedure 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, th
17、e expression “Administration” is used for conciseness to indicate both 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 Recommendation may involve the use of a cla
18、imed Intellectual Property Right. The ITU takes no position concerning the evidence, vaiidity 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
19、ITU had not 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 information and are therefore strongly urged to consult the TSB patent database. O ITU 1998 A
20、ll 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 the ITU. 11 ITU-T Rec. X.226 (1994)/Amd.l (1997 E) - STD-ITU-T RECMN X.226 AilD II-ENGL 1777 4
21、8b259.L UbY35i7 2b7 BIP CONTENTS I) Subclause 2.1 . 2) Subclause 2.3 . 3) Subclause 3.4 . 4) Subclause 3.5 . 5) Subclause 4.2 . 6) Subclause 4.3 . 7) Subclause 5.4 . 5.4 bis Protocol options . 5.4 bis . 1 Nominated context protocol option 5.4 bis.2 Short encoding protocol option . 5.4 bis.3 Packed e
22、ncoding rules protocol option . 5.4 bis.4 Null-encoding protocol option . Short-connect protocol option . . 5.4 bis.5 8) Subclause 6.2.1 9) Subclause 6.2.2 1 O) Subclause 6.2.3 . . 1 1) Subclause 6.2.2 . 12) Subclause 6.2.2.16 . 13) Subclause 6.2.3.13 . 14) Subclause 6.2.5 . 15) Subclause 6.2.6 16)
23、Subclause 6.2.7.2 . 17) Subclauses 6.2.8 through 6.2.11 . 18) Subclauses 6.4.4.2, 6.4.4.3 and 6.4.4.6 . . 19) Subclause 7.1.1.1 . . 20) Subclause 7.1.2.1 . 21) Subclauses 7.1.4 through 7.1.6 . 22) Subclause 8.1.1 . . 23) Subclause 8.1.2 . . 24) Subclauses 8.1.4 through 8.1.6 . 25) Subclause 8.2 . .
24、8.2 bis Short-encoding PPDUs . 26) Subclause 8.3.1 . 27) Subclause 8.3.3 28) Subclause 8.4.1.2 29) Subclause 8.4.1.3 . Page 1 1 1 2 2 2 2 2 3 3 3 3 4 4 4 5 5 5 5 6 6 7 8 9 10 10 10 11 12 12 13 14 14 15 15 15 ITU-T Rec . X.226 (1994)/Amd.l (1997 E) . 111 . 30) 3 1) 32) 33) 34) 35) 3 6) 37) Subclause
25、8.4.1.4 . Subclause 8.4.2.2 . Subclause 8.4.2.5 . Subclauses 8.4.4 through 8.4.4.2 Subclause A.4.1.2 . Subclause AS . Subclause AS . 2 Subclause A.6 . Page 15 15 15 16 16 16 16 17 iv ITU-T Rec . X.226 (1994)/Amd.l (1997 E) - ISOIEC 8823-1 : 1994/Amd.l : 1998 (E) INTERNATIONAL STANDARD ITU-T RECOMMEN
26、DATION INFORMATION TECHNOLOGY - OPEN SYSTEMS INTERCONNECTION - CONNECTION-ORIENTED PRESENTATION PROTOCOL: PROTOCOL SPECIFICATION AMENDMENT 1 Efficiency enhancements . 1) Subclause 2.1 Add the following references by numerical order: - ITU-T Recommendation X.691 (1995) I ISO/IEC 8825-2: 1995, Informa
27、tion technology - ASN.1 encoding rules: Speclfication of Packed Encoding Rules (PER). - ITU-T Recommendation X.217 (1995)Amd.l (1996) 1 ISO/IEC 8649:1996/Amd.l:1997, Information technology - Open Systems Interconnection - Service definition for the Association Control Service Element -Amendment I: S
28、upport of authentication mechanismsfor the connectionless mode. ITU-T Recommendation X.227 (1995)Amd. 1 (1996) I ISO/IEC 8650-1 : 1996/Amd. 1 : 1997, Information technology - Open Systems Interconnection - Connection-oriented protocol for the Association Control Service Element: Protocol specificati
29、on -Amendment I: Incorporation of extensibility markers. ITU-T Recommendation X.216 (1994)/Amd.l (1997) 1 ISO/IEC 8822:1994/Amd.l:1997, Information technology - Open Systems Interconnection - Presentation service definition - Amendment I : Efficiency enhancements. - - 2) Subclause 2.3 Add the follow
30、ing references by numerical order: - ITU-T Recommendation X.2 16 (1 994)/Addendum 1 (1 995), Service definition for Presentation layer eficiency enhancements. ITU-T Recommendation X.225 (1995)/Addendum 1 (1 995), Protocol specrfication for Session layer efficiency enhancements. - 3) Subclause 3.4 Ad
31、d the following new item at the end of the list: 1) Upper-layer context specification. Consequently, item k) should have, at the end, a semi-colon instead of aperiod. ITU-T Rec. X.226 (1994)/Amd.l(1997 E) 1 - - STD*ITU-T RECNN X-22b AND 1-ENGL 1777 I4862573 0643551 852 S ISO/IEC 8823-1 : 1994/Amd.l
32、: 1998 (E) 4) Subclause 3.5 Insert the following de$nition by numerical order: 3.5.3 bis nominated context: A member of the Defined Context Set can be nominated by either PPM as its nominated context. There are independent nominated contexts for each direction of communication. There are no nominate
33、d contexts unless the nominated context protocol option is selected on the connection. If all the presentation data values in the User-data of PPDU are in the nominated context of the sender, alternative presentation PCI may be used to convey the User-data. Add the following de$nitions after 3.5.14:
34、 3.5.15 nominated context protocol option: An option of the presentation protocol that uses an efficient identification of the presentation context of user data when a single presentation data value is present in the user data of a primitive. 3.5.16 short-encoding protocol option: An option of the p
35、resentation protocol that uses efficient encoding of a PPDU containing a single presentation data value. 3.5.17 PPDUs are encoded using the ASN. 1 Packed Encoding Rules. 3.5.18 establishment, that permits a data transfer phase with zero presentation protocol control information. 3.5.19 during connec
36、tion establishment, of the null-encoding protocol option. packed encoding protocol option: An option of the presentation protocol under which the Presentation null-encoding protocol option: An option of the presentation protocol, negotiated during connection short-connect protocol option: An option
37、of the presentation protocol that permits an efficient negotiation, 5) Subclause 4.2 Add the following PPDUs at the end of the list: SHORT-CP PPDU Short Connect PPDU SHORT-CPA PPDU SHORT-CPR PPDU Short Connect Accept PPDU Short Connect Reject PPDU 6) Subclause 4.3 Insert the following abbreviations
38、by alphabetical order: BER Basic Encoding Rules PER Packed Encoding Rules 7) Subclause 5.4 Insert the following new subclauses after 5.4: 5.4 bis Protocol options Protocol options are elements of procedure defined in the Protocol Specification. Some have no effect on the support of the Presentation
39、Service; others imply restrictions on the support of Presentation Service or can only be used with other options that restrict the service. The options that do not affect support of the Presentation Service can be negotiated at presentation-connection establishment by the Presentation protocol itsel
40、f. These include the nominated context, short-encoding and packed encoding options. The null-encoding option supports a restricted subset of the Presentation Service. It can. be negotiated at presentation connection establishment. The short-connect option can only be used to establish a connection t
41、hat will use the null-encoding option. 2 ITU-T Rec. X.226 (1994)lAmd.l (1997 E) STD-ITU-T RECNN X.22b AND 1-ENGL 1977 48b257i 0b1i3551i 778 I ISOAEC 8823-1 : 1994lAmd.l : 1998 (E) All options apart from short-connect may be negotiated using the fast-associate mechanism (see 6.2.6.9). The short-conne
42、ct option and the fast-associate mechanism are mutually exclusive. All options may be the subject of a priori agreement. NOTE I - The short-encoding and short-connect protocol options are completely separate. Short-encoding applies to the user-data of any PPDU on an established connection. Short-con
43、nect applies to the establishment of a connection that will use the null-encoding option. NOTE 2 -The fast associate mechanism (see 6.2.6.9) is not considered a Presentation protocol option as it is implemented in the Session layer. It can be used to establish a presentation connection that uses any
44、 combination of the options, except short-connect. 5.4 bis.1 Nominated context protocol option This protocol option allows each of the protocol machines to choose one of the presentation contexts of the DCS as its nominated context. The nominated context affects the presentation protocol control inf
45、ormation that conveys the User-data, in circumstances defined in 8.4. There are independent nominated contexts for each direction -the initiators nominated context applies to User-data sent by the connection-initiator, the responders nominated context applies to User-data sent by the connection-resp
46、onder. Even when the protocol option has been selected, there need not be a nominated context for either or both PPMs. . ,. The nominated context protocol option does not affect the Presentation Service. It has no implications for which session functional units are used. 5.4 bis.2 Short encoding pro
47、tocol option This protocol option allows use of the Short-encoding form of User-data for any PPDU for which it is defined if the User-data contains only one presentation data value. This protocol option does not affect the Presentation service. It requires support of the Special User-data parameter
48、of the Session primitive whose User-data is the PPDU. 5.4 bis.3 Packed encoding rules protocol option When this protocol option is selected, the PPDUs that are specified in ASN.1 in 8.2 are encoded using the Packed Encoding Rules. When the protocol option is not selected, these PPDUs are encoded usi
49、ng the Basic Encoding Rules. The negotiation of the Packed Encoding Rules protocol option is described in 6.2.6.8. 5.4 bis.4 Null-encoding protocol option When this protocol option is selected, no presentation protocol control information is conveyed over the established presentation connection. In particular, no PPDUs associated with the normal and abnormal release of the connection are conveyed. The null-encoding protocol option is used on an established connection. The use of the option restricts support of the Presentation service an
