ITU-T T 571-1992 Terminal Characteristics for the Telematic File Transfer within the Teletex Service - Terminal Equipment and Protocols for Telematic Services (Study Group VIII 13 .pdf

1、CCITT RECMN*T.573 72 m 4862533 0577358 57T = INTERNATIONAL TELECOMMUN CATION UN ION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE TERMINAL EQUIPMENT AND PROTOCOLS FOR TELEMATIC SERVICES T.571 (09/92) TERMINAL CHARACTERISTICS FOR THE TELEMATIC FILE TRANSFER WITHIN THE TELETEX

2、 SERVICE I Recommendation T.571 CCITT RECMN*T.571 92 W 4862591 0579359 406 = FOREWORD The CCT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the Intemational Telecommunication Union (). CCIiT is responsible for studying technical, operating and tariff ques

3、tions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by t

4、he members of CCiT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). Recommendation T.571 was prepared by Study Group VI11 and was approved under the Resolution No. 2 procedure on the 18 September 1992. CCiT NOTE In this Recommendation, the

5、 expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency. O ITU 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, includi

6、ng photocopying and microfilm, without permission in writing from the ITU. CCITT RECMN*T.571 92 m 4862591 0579360 128 m CONTENTS INTRODUCTION 1 2 3 4 5 6 7 8 9 scope . Normative references . Definitions . 3.1 basic transfer mode . 3.2 document transfer mode 3.3 binary file transfer . 3.4 EDIFACT . 3

7、.5 control document 3.6 mandatory . 3.7 option al . Abbreviations . File Transfer 5.1 Essential features 5.2 Protocol aspects 5.3 Control document (optional) . Mechanism used 6.1 Capabilities exchange . 6.1.1 6.1.2 6.1.3 BTM capability negotiation (mandatory) BF capability negotiation (optional) . E

8、DIFACT capability negotiation (optional) Invokation (start of a fiie) 6.2.1 BTM indication invokation (optional) 6.2.2 BFT indication invokation (optional) . 6.2.3 6.2.4 File name indication invokation (optional) . 6.2.5 6.2 EDIFACT indication invokation (optional) Free user field invokation (option

9、al) . 6.3.1 File management . 6.3 File transfer 6.4 End of the telematic file transfer . 6.5 Connection interrupt . Log books (if available) Communication Identification Line (CIL) Coding and structure of the control document 9.1 Telematic file transfer parameter coding . 9.1.1 Parameters used in CD

10、CLRDCLP . 9.1.2 Parameters used in CDSKDC Recommendation T.571 (09/92) Page 11 1 1 1 1 2 2 2 2 2 2 2 3 3 3 4 4 4 4 4 4 5 5 5 5 5 5 5 5 6 6 6 6 6 7 7 8 i INTRODUCTION This Recommendation defines the general rules required for the implementation of the Telematic file transfer for Teletex applications.

11、 It defines the technical mechanisms and coding used. Note - The use of this Recommendation for Facsimile Group 4 is for further study. 11 Recommendation T.571 (9B2) CCITT RECMN*T.573 72 4862593 O579362 TTO m Recommendation T.571 TERMINAL CHARACTERISTICS FOR THE TELEMATIC FILE TRANSFER Wll“iN THE TE

12、LETEX SERVICE (1992) 1 Scope This Recommendation contains technical requirements for implementing the functionalities allowed by the telematic file transfer. The service requirements for telematic file transfer are described in Recommendation F.551. It explains the general and equipment features for

13、 the telematic file transfer which are required from a service point of view. The objective is to allow the transmission of a data file using the telematic file transfer possibilities with or without additional information concerning the file to be transmitted. 2 Normative references This Recommenda

14、tion contains provision which, through references in the text, constitue provisions of this Recommendation. At the time of publication, the editions indicated were valid. Ali Recommendations are subject to revision. The CCITT secretariat maintains a list of the currently valid CCITT Recommendations.

15、 CCIIT Recommendation T.62 (1988), Control procedures for Teletex and G.4 facsimile services. CCITT Recommendation T.61 (1988), Character repertoire and coded character sets for the international Teletex service. CCITT Recommendation T.50 (1988), International Alphabet No. 5. CCITT Recommendation F.

16、200 (1988), Teletex service. CCIV Recommendation X.209 (1988), Specification of basic encoding rules for Abstract Syntax Notation One (ASN.). CCITT Recommendation T.434 (1992), Specijcation of binaryfile transfer. ISO/IEC 9735: 1990, Electronic data interchange for administration commerce and transp

17、ort (EDIFACT) - Application level syntax rules. CCITT Recommendation F.551 (1992), Service Recommendation for the Telematic File Transfer within the Telefax 3, Telefax 4, Teletex and Message Handling Services. Definitions For the purposes of this Recommendation, the following definitions apply. basi

18、c transfer mode It provides the user of a telematic equipment with a means to exchange files of any kind (binary files, wordprocessor native format documents, bitmaps, etc.) without additional information. Recommendation T.571 (09/92) 1 CCITT RECMNrT.573 92 4862593 0579363 937 3.2 document transfer

19、mode It provides the user of a telematic equipment with a means to exchange file of any kind with additional information, readable by the user or possibly automatically processed, included in a control document. In the Teletex environment the DTM is merged to the BTM feature. 3.3 binary file transfe

20、r It provides the user of a telematic equipment with a means to exchange files of any kind with additional information automatically processed on the receiving side. The coding rules which apply to these additional information are technically aligned of those of FTAM (Recommendation X.209 5) coded.

21、The binary file transfer is described in Recommendation T.434. Within thecontext of this Recommendation the diagnostic message mentioned in Recommendation T.434 is not used. 3.4 EDIFACT It provides the user of a telematic equipment with a means to exchange files according to ISOLEC 9735 8 rules. 3.5

22、 control document It is a structured document which can either be used for automatic processing or, for file in an end-to-end communication or within a communication with an intermediate store-and-forward equipment. 3.6 3.7 4 BFT BTM CDC CDCL CDS CDPB CIL mandatory The feature described shall be use

23、d. optional The feature described can be used. Abbreviations The foliowing abbreviations shall apply: Binary File Transfer Basic Transfer Mode Command Document Continue Command Document Capability List Command Document Start Command Document Page Boundary Communication Identification Line EDJFACT IA

24、5 International Alphabet No. 5 LI Length Indicator EGI Parameter Group Identifier Electronic Data Interchange for Administration, Commerce and Transport 2 Recommendation T.571 (09B2) CCITT RECMNaT.571 92 E 48b2591 05793b4 873 E PV Parameter Value RDCLP Response Document Capabiiity List Positive RDEP

25、 Response Document End Positive 5 File Transfer 5.1 Essential features a) The transmission of a data file using the telematic file transfer possibilities consists of the transmission of the data file itself and, on user requirement, the transmission of information describing the file. The content of

26、 the data file may be any kind of coding. For the time being, three types of data files are taken into account. They ate: - Basic Transfer Mode (BTM); - Binary File Transfer (BF); - EDJFACT. b) c) The BTM mode is the minimum requirement that an equipment must provide for participating in the Telemat

27、ic File Transfer. Information describing the file may be found in Recommendation T.62 i session proiocol element (i.e file name, tree user field). Additional information concerning a more detailled file description ate defined in a control document (e.g file type, file coding, editor program, etc.).

28、 In case of BFT, the data structure contains attributes describing the file. These attributes are coded in ASN1 151. d) e) fl 5.2 Protocol aspects a) b) The telematic file transfer for Teletex equipments is based on Recommendation T.62 i session. Teletex or group 4 facsimile equipments may negotiate

29、 one or more of the features mentioned above. The mechanism used is the same as the one used for the private mode negotiation i.e CDCL (Command Document Capabiiity List) or RDCLP (Response Document Capability List Positive). The actual transmission (invokation) of one of the data files (BTM, BET, ED

30、IFACT) is indicated by means of a parameter within the Command Document Start (CDS) or Command Document Continue (CDC) session protocol element. Regarding to the case of the data file indication the foliowing rules apply: - - c) the capability negotiation must bave succeeded; only one data fide indi

31、cation per transmission. The implementation of BTM is the minimum feature. - When the use of BTM has been agreed between the terminal equipments, a BTM indication may be transmitted in the CDS/CDC protocol elements. Information like file name and free user field may also be transmitted in the CDS/CD

32、C protocol elements. Additional information, associated to the file to be transmitted, are described in the control document. - When the use of BFT has been agreed between the terminal equipments, a BFT indication may be transmitted in the CDS/CDC protocol elements. No additional information is tran

33、smitted in CDS/CDC protocol elements. Recommendation T.571 (09/92) 3 CCITT RECMN*To571 92 I 4862591 0579365 70T - When the use of EDIFACT has been agreed between the terminal equipments, an EDIFACT indication may be transmitted in the CDS/CDC protocol elements. Information like file name and free us

34、er field may also be transmitted in the CDS/CDC protocol elements. The telematic file transfer allows to link automatically the different parts of a document when it is transmitted in several parts. When telematic file transfer is used, the negotiation of the receiving memory capacity is strongly re

35、commended. Furthermore, a binary file which is not completely transmitted cannot be processed. When the telematic file transfer is supported, it should have priority over the manufacturer private mode. d) e) 0 5.3 Control document (optional) during the same coinmunication, prior to the file (see cla

36、use 7). To transfer a file using the BTM mode, a control document containing additional information may be sent The definition of the control document content is based on a standardized file description. The coding shall be in line with Recommendation T.61 2. The additional information which may be

37、transmitted using a control document is defined in Recommendation F.55 1 8. 6 Mechanism used 6.1 Capabilities exchange capabilities. Before sending any kind of file by the telematic file transfer features, it is mandatory to check the transmitting 6.1.1 BTM capability negotiation (mandatory) After t

38、he session establishment, the calling equipment shall negotiate the BTM mode. To this end, a BTM parameter (KI = E3, FI = E9, PI = EA, see 9.1.1) shall be sent in the CDCL protocol element. If the called equipment provides the BTM mode, it sends back this parameter in the response RDCLP. If there is

39、 no BTM parameter in the RDCLP, the Telematic File Transfer will not be allowed. 6.1.2 BFT capabiliv negotiation (optional) A BFT parameter (pG1 = E3, PI = E9, PI = EE, see 9.1.1.) is sent in the protocol element CDCL indicating the capability of the calling equipment to transfer BFT files. The rule

40、s applying on BF are described in Recommendation T.434 6. If the called equipment provides the BFT capability, it sends back the same BIT parameter in the RDCLP If there is no BFT parameter in RDCLP, the binary file transfer will not be allowed. protocol element. 6.1.3 EDIFACT capability negotiction

41、 (optional) An EDIFACT parameter (PGI = E3, PI = E9, PI = EA, PI = EB, see 9.1.1) is sent in the protocol element CDCL indicating the capability of the calling equipment to be able to cope with EDIFACT files. The rules applying on EDIFACT are described in ISOKEC 9735 7. If the called equipment provi

42、des the EDIFACT capability, it sends back the same EDIFACT parameter in the RDCLP protocol element. If there is no EDIFACT parameter in RDCLP, the EDIFACT file shall not be sent. Nevertheless, this file can be transferred, on user request, without the EDIFACT parameter as any other kind of file by u

43、sing the BTM mode. 4 Recommendation T.571 (09/92) CCITT RECMN*T.571 92 E4 48b259L 0579366 b4b 6.2 Invokation (start of afile) 6.2.1 BW indication invokation (optional) One or several files may be transferred in the same session. The BTM is invoked by CDS or CDC canying the BTM indication parameter (

44、EI = E3, P1= E9, PI = EA, see 9.1.2). The BTM parameter or any other additional information shall only be used in CDS or CDC when the BTM was successfully negotiated in the CDCLRDCLP protocol elements. 6.2.2 BFT indication invokation (optional) The terminal equipment invokes the BF using the BF indi

45、cation parameter in CDS or CDC protocol elements (PGI = E3, PI = E9, PI =EE, see 9.1.2). 6.2.3 EDIFACT indication invokation (optional) The terminal equipment invokes the EDIFACT using the EDIFACT indication parameter in CDS or CDC protocol elements (EI = E3, PI = E9, PI =EA, PI = EB, see 9.1.2). 6.

46、2.4 File name indication invokation (optional) A file name may be transferred together with BTM parameter in order to identify a transparent file. The file name is also useful for facilitating the relationship between the file name attribut in the control document (if it is present) and the file. So

47、, the file name used in the control document and the file name parameter In CDS or CDC should be identical. This information is transferred in CDS or CDC (PI = EC, see 9.1.2). Recommendation T.61 2 coding shall be used. preferably with characters of the IA No. 5 Recommen- If the called equipment has

48、 already in its receiving memory file a file, the name of which is identical to the For assignement of a filename to a basic Teletex document, (i.e. transmitted in the Teletex service) the FILE- In this case the CDS/CDC command contains only the parameters “new mode”, “unique identification” and dat

49、ion T.50 3. name contained in the file name parameter, it is necessary to avoid the destruction of these files. name” parameter may also be used. “file name”. 6.2.5 Free user jeld invokation (optional) On the sending side, the user may need to input some additional information (e.g reference, which software is running, etc.) in order to help the recipient of the file. This information is transferred in CDS or CDC (PI = ED, see 9.1.2). Recommendation T.61 2 coding shall be used. preferably with characters of the IA No. 5 Recommen- On the receiving si