1、ITU-T RECIN*T*523 93 m 4862591 0594092 235 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU T.523 (03/93) TELEMATIC SERVICES TERMINAL EQUIPMENTS AND PROTOCOLS FOR TELEMATIC SERVICES COMM UN CATION APPLICATION INTERWORKING PROFILE DM-1 FOR VIDEOTEX ITU-T R
2、ecommendation T.523 (Previously “CCITT Recommendation”) ITU-T RECHNbT.523 93 4862591 0.594093 171 FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tari
3、ff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce
4、 Recommendations on these topics. ITU-T Recommendation T.523 was revised by the ITU-T Study Group VI11 (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCIT ceased to exist
5、as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no ch
6、ange has been made in the text to references containing the acronyms “CCITT, CCIR or XFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. 2 telecommunication adminis
7、tration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1994 All rights reserved, No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including pho
8、tocopying and microfilm, without permission in writing from the ITU. ITU-T RECMNtT.523 93 = 4862591 0594094 008 1 2 3 4 5 6 7 8 9 10 CONTENTS scope Field of application References Definitions Overview of communication profile DM-1 Basic communication requirements for DM- 1 . 6.1 DTAM functionalities
9、 . 6.2 ACSE functionalities 6.3 Presentation functionalities . 6.4 Session functionalities Communication procedure for DM-1 . 7.1 General communication procedure . 7.2 Application-association establishment 7.3 Application-association terminate and abort 7.4 Data transmission Elements of procedure 8.
10、1 Application-association establishment 8.2 Application-association termination . 8.3 Application-association abort . 8.4 Data transmission Actions of the EH and the LH 9.1 EH action 9.2 LH action 9.3 List of permissible actions on VIA structure elements in both hosts Object identifier . Annex A . A
11、bstract syntax definition of videotex specific information . Encoding of user information associated with D-INITIATE services Encoding of user information associated with D-ABORT services . A.l A.2 Recommendation T.523 (03/93) Page 1 1 1 2 2 2 2 3 3 3 3 3 4 4 4 10 10 12 13 13 16 16 17 17 18 19 19 19
12、 i ITU-T RECMN*T-523 93 48b259L 0594095 T44 a Recommendation T.523 COMMUNICATION APPLICATION PROFILE DM-I FOR VIDEOTEX INTERWORKING (Melbourne, 1988; revised at Helsinki, 1993) 1 Scope 1.1 The T.400-Series Recommendations generally defines open document architecture (ODA), document architecture oper
13、ations and DTAM servicdprotocol for document architecture transfer and manipulation under the telematic communication environment. 1.2 manipulation to specify an interactive communication profile based on DTAM between videotex gateway systems. This Recommendation defines a communication application
14、profile DM- 1 for document unconfirmed 1.3 described in this Recommendation. The use of Recommendations X.215, X.225, X.216, X.226, X.217 and X.227 for this communication profile is 2 Field of application 2.1 The communication application profile DM- 1 enables document manipulation for documents whi
15、ch are represented in accordance with the document application profile defined by Recommendation T.504, and the operational application profile defined by Recommendation T.541. 2.2 The ODA documents that are manipulated should be in formatted form. 2.3 videotex gateways, representing the external ho
16、st (EH) and the local host (LH). The field of application of this Recommendation is the international videotex interworking service between 2.4 the Recommendation T.564 which defines gateway characteristics for videotex inter-working. Videotex communication procedure is based on the model defined in
17、 this Recommendation in accordance with 3 References - Rec. T. 101 International interworking for videotex services - Rec. T.430-Series Document transfer and manipulation (DTAM) - Rec. T.504 Document application profile for videotex interworking - Rec. T.54 1 Operational application profile for vide
18、otex intenuorking - Rec. T.564 Gateway characteristics for videotex interworking - Rec. X.215 Session service definition for open systems interconnection for CCIT applications - Rec. X.225 Session protocol specification for open systems interconnection for CCZT applications - Rec. X.216 Presentation
19、 service definition for open systems interconnection for CClT applications - Rec. X.226 Presentation protocol specijcation for open systems interconnection for CCZ7T applications Recommendation T.523 (OW3) 1 ITU-T RECMNmT-523 93 W 4862593 0594096 980 W - Rec. X.217 Association control service defini
20、tion for open systems interconnection ,for CCIT applications - Rec. X.227 Association control protocol specification for open systems interconnection for CCIT applications - Rec. X.208 Specification of abstract syntax notation one (ASN. i) Rec. X.209 Specijcation of basic encoding rules for abstract
21、 syntax notation one (ASN. I) - 4 Definitions Terms and their definitions are defined by the Recommendations listed above. 5 Overview of communication profile DM-1 5.1 Communication profile DM-1 defines the communication functionalities which provide a real time remote document manipulation on ODA a
22、nd operational structure documents by create, delete, modify and call operations between videotex gateways under OS1 ACSE and presentation communication support functions (normal mode defined in Recommendation T.432). These operations are the unconfirmed type of manipulation. 5.2 This profile define
23、s the communication model which consists of the local host DTAM user and the external host DTAM user as illustrated in Figure 1. Either the LH or the EH is capable of managing the initiation and termination of application-association. At the association establishment phase, initial VIA structures ar
24、e automatically generated in both hosts. 5.3 The owner of the data token, managed by the DTAM token control function, is able to manipulate ODA and operational structure documents which are directly mapped from VIA operations defined in the Recommendation T.564. 5.4 The manipulation provides the ope
25、rations which can be applied to one or more constituents of the ODA document and/or the operational structure. In this profile, these Operations do effect addition, deletion or modification of constituent to a document which existed identically between both hosts. 5.5 When the data token belongs to
26、the LH DTAM user, only modify operations on operational structure are allowed to be used by the LH DTAM user. On the other hand, the EH DTAM user is able to use all of the operations defined in DTAM when it has the data token. 6 Basic communication requirements for DM-1 DM-1 is defined under the fol
27、lowing OS1 communication environment. Mapping rules of DTAM APDUs into/out of the ACSE and presentation layer are used as defined in Recommendation T.433. 6.1 DTAM functionaties The following DTAM functionalities defined in Recommendation T.432 are basic requirements for this communication profile D
28、M- 1 : i) document unconfirmed manipulation by using create, modify, delete and call operations; ii) association use control; iii) token management for dialogue control; iv) typed data transmission. 2 Recommendation T.523 (03D3) ITU-T RECMN*T.523 93 = 48b2591 059q097 817 = Interactive videotex syste
29、m A interaciive videatex system B PSAP - X.216 PSAP - X226: Proiocd FIGURE 1n.523 A model of conmnuiication application profue DM-1 for videotex interworkhg 6.2 ACSE functionaiities The basic functionalities of the association control service element defined by Recommendations X.217 and X.227 are us
30、ed. 6.3 Presentation functionaiities The kernel functional unit is used as defined by Recommendations X.216 and X.226. Recommendations X.208 andX.209 are used for the definition of abstract notation and basic encoding rules of abstract notation respectively for DM- 1. 6.4 Session functionalities The
31、 kernel functional unit, two ways alternate functional unit and typed data functional unit are used in accordance with Recommendations X.215 and X.225. 7 Communication procedure for DM-1 7.1 General communication procedure The general communication procedure for videotex gateway application is defin
32、ed in line with the basic procedure in Recommendation T.432. The procedure consists of: - application-association establishment; - application-association termination; Recommendation T.523 (03/93) 3 ITU-T RECMN*T-523 93 = 4862591 0594098 753 - application-association abort; - datatransmission. 7.2 A
33、pplication-miation establishment A communication normally begins with the establishment of application-association from the LH or EH DTAM user to initialize the communication environment and to set the initial parameters and the VIA structures being used. The initial data token is assigned to the EH
34、 DTAM user. Afer the establishment of application-association, both DTAM users move to the data transmission phase. 7.3 Appiication-association terminate and abort The DTAM application-association may be normally terminated by either the LH or the EH DTAM user subject to the owning of the data token
35、. The DTAM application-association may also be abruptly terminated by either the LH or the EH DTAM user or provider using the appropriate DTAM abort services. 7.4 Data transmission 7.4.1 General Videotex gateway application provides the following communication functions in the data transmission phas
36、e: manipulation of display information; manipulation of data entry information; manipulation of application control memory information; manipulation of special terminal facilities information; manipulation of administrative information; exchange of over limit information (for further study); transmi
37、ssion of asynchronous message. 7.4.2 Manipulation of display information Display is performed by VIA operations, defined in Recommendation T.564. initiated by the external host on the display structure. To perform VIA operations on the display stmcture the EH uses D-CREATE, D-MODIFY, D-DELETE or D-C
38、ALL service primitives under data token control. 7.4.3 7.4.3.1 General Recommendation T.564 defines the following four types of data entry: Manipulation of data entry information I) 2) data entry type 1 - information retrieval; data entry type 2 - data collection; 3) data entry type 3 - data entry o
39、n the fly; 4) data entry type. 4 - duplex data entry. These data entry types are categorized into half duplex mode (data entry type 1. 2 and 3) and duplex mode (data entry type 4). 4 Recommendation T.523 (03/93) ITU-T RECMN*T-523 93 = Y862591 O594099 b7T The EH may use D-CREATE, D-MODIFY, D-DELETE,
40、D-CALL to perform VIA operations on each structure element of the data entry structure, except modifying the RESULT-SE and its associated content portion. Halfduplex mode of data entry provides the dialogues between the LH and the EH under the data token control. Data entry is performed from the LH
41、by VIA operations via DTAM manipulation (D-MODIFY) on the data entry structure. In this case the EH should give the data token to the LH to perform data entry. Duplex mode of data entry is not dependent upon the token control. Data entry is performed from the LH by the use of typed data and the data
42、 token is always located at the EH side. 7.4.3.2 Management of data entry mode The management of the data entry modes is bound to the following rule: i) ii) iii) i v) v) The LH issues the parameter of “data entry mode” to indicate the data entry capabilities at the LH side in the DTAM association es
43、tablishment phase. This parameter is a choice of a) half duplex mode b) duplex mode and c) half duplex and duplex modes. the EH recognizes the capabilities of data entry mode which is capable to be managed by the LH. It is not necessary to inform the LH of the EH capabilities of the data entry mode;
44、 if the LH indicates the only half duplex mode and selects the application based on the duplex mode, the EH may refuse :o connect with the selected application from the LH; if the LH indicates the only duplex mode and selects the application based on the half duplex mode, the EH may refuse to connec
45、t with the selected application from the LH; if the LH indicates both modes, all the applications based on the half duplex or duplex modes are available to the LH. 7.4.3.3 Operation of data entry in half duplex mode (type 1,2,3) In data entry type 1 or 3, the entered data are sent from the LH to the
46、 EH using D-MODIFY for the RESULT-SE and the content portion associated to the RESULT-SE. In data entry type 2, the entered data are sent from the LH to the EH using D-MODIFY for the RESULT-SE and the content portions associated with the entered fields and the RESULT-SE (if necessary). The EH gives
47、the token to the LH to enable the LH to send the entered data. The LH gives the token to the EH after having completed the data entry (i.e. after having initiated the appropriate D-MODIFY corresponding to the SES concerned with data entry). Examples are given in Figures 2 and 3. 7.4.3.4 Operation of
48、 data entry in duplex mode (type 4) When the data entry type attribute of the DATA-ENTRY-PROGRAM-SE is set the data entry type 4, the LH sends the entered data and the termination reason in D-TYPED-DATA with the termination reason associated. The data token remains assigned to the EH. An example is
49、given in Figure 4. When the EH resets the data entry type attribute to another type (I, 2 or 3) under the condition that both modes are available at the LH, the LH stops sending data in D-TYPED-DATA and uses again D-MODIFY to send the entered data. The EH ignores the possible colliding D-TYPED-DATA. Recommendation T.523 (0393) 5 ITU-T RECMNlT-523 93 = 4862593 0594300 333 -FY req 4- I D-TOKEN-GIVE req i 4 I I I I I I D D I I I I I I I I b D-MODIFY ind + D-MODIFY ind b DTOKEN-GIVE ind i I I I I D-MODIFY req 4 : sendsthe D-MODIFY req requested 4 infomiaon D-MODIFY req I - I DTAM SeNiCe
