IMPORT R:\\ART\\W INTERNATIONAL TELECOMMUNICATION UNION MF\\ITU.WM F \* mergeforma t CCITT F.87 THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE TELEGRAPH AND MOBILE SERVICES OPERATIONS AND QUALITY OF SERVICE OPERATIONAL PRINCIPLES FOR THE TRANSFER OF MESSAGES FROM TERMINALS ON THE TELEX NETWORK TO GROUP 3 FACSIMILE TERMINALS CONNECTED TO THE PUBLIC SWITCHED TELEPHONE NETWORK Recommendation F.87 IMPORT Geneva, 1991 R:\\ART\\ WMF\\CCIT TRUF.WMF \* mergeform at Printed in Switzerland FOREWORD The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT 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 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 the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). Recommendation F.87 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 11 of March 1991. ___________________ CCITT NOTE In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. F ITU 1991 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 the ITU. PAGE BLANCHE Recommendation F.87 Recommendation F.87 OPERATIONAL PRINCIPLES FOR THE TRANSFER OF MESSAGES FROM TERMINALS ON THE TELEX NETWORK TO GROUP 3 FACSIMILE TERMINALS CONNECTED TO THE PUBLIC SWITCHED TELEPHONE NETWORK The CCITT, considering (a) the need to allow the transfer of messages from terminals of the international telex service to Group 3 facsimile terminals on the public switched telephone network; (b) that Recommendations F.60, F.69 and other relevant Recommendations govern operation of the international telex service; (c) that Recommendation E.163 defines the numbering plan for the international telephone service; (d) that Recommendation F.72 defines the general principles and operational aspects of international telex store and forward; (e) that Recommendations F.160 and F.180 define the general operational provisions for the international public facsimile services; (f) that Recommendation T.4 defines the standardization of Group 3 facsimile apparatus; (g) that Recommendation T.30 defines the procedure for document facsimile transmission in the public switched telephone network; (h) that technical aspects of the international telex service are described in R-, S- and U-Series Recommendations, unanimously declares the view (1) that there are benefits in standardizing the operational procedures for a terminal of the international telex service to transfer a message, across international boundaries, to a Group 3 facsimile terminal on the public switched telephone network; (2) that where this message transfer service is provided, the preferred operational procedures are laid down in this Recommendation. 1. Scope 1.1 The procedures defined in this Recommendation enable telex subscribers to transfer messages to Group 3 facsimile terminals connected to the PSTN, on a store and forward basis. 1.2 The interworking shall be established by provision of a telex/facsimile interworking function (FAXIWF). 1.3 International access to the FAXIWF will normally be provided via the telex network (see Figure 1/F.87). Bilateral agreement may be required in the event that other than normal telex service agreements are required. 1.4 For telex subscribers accessing a FAXIWF in their own country, national or international destinations may be specified, with international interworking being implemented via the PSTN. See Figure 2/F.87. Figure 1/F.87 = 7,5 cm Figure 2/F.87 = 8 cm 1.5 The Administration providing the FAXIWF shall be responsible for any necessary barring of international access. 2. Service principles 2.1 The basic service offered is: — acceptance of messages from the telex network, with accompanying fax (PSTN) addressing information; — delivery of these messages to the requested facsimile terminal, with retries if necessary; — notification message sent to the originator when the message delivery attempt fails and, optionally, when it succeeds. 2.2 A single-stage selection procedure may be used employing normal telex procedures where the requested facsimile machine is addressed using a telex number. 2.3 A two-stage selection procedure may be used whereby a call from the telex network gains access to the FAXIWF in the first stage of selection and inputs the called address(es) and message(s) in the second stage of selection, after the return of a call connect signal. To the extent possible, this procedure has been aligned with that for telex store-and-forward facilities defined in Recommendation F.72. 2.4 Message input from both manual and telex automatic emitting devices should be possible. 2.5 Messages deposited into the FAXIWF will be sub-divided by the FAXIWF into "pages" which serve as physical "A4" size pages as received at the fax terminal. styleref head_footRecommendation F.87PAGE 7 Otherwise, the input format shall be preserved. A page should normally comprise 55 lines of text (of 4.23 mm pitch), or part thereof for pages with fewer than 55 text lines. Upon transmission, it is preferred to have both message reference and pagination information inserted in a header line on each page. 2.6 In addition to delivering the message as pages of text to the specified fax terminal(s), the FAXIWF may optionally prepare and transmit a "header page" consisting of at least: — message reference information (which may include the legal time and date of acceptance); — calling party identification (telex answerback and recall information, if necessary); — indication of number of pages in message; — specified facsimile terminal (PSTN) address; — optional customer attention information field (see S 3.2.4). 2.7 Where a header page is not transmitted, the FAXIWF should attach a herald to the beginning of the message indicating the calling party identification (telex answerback and recall information, if necessary). 2.8 The FAXIWF will attempt to deliver the message as soon as operationally feasible. Deferred delivery may also be provided. 3 Service facilities In the following section, the symbol * indicates that the facility is not normally applicable for one-stage selection. 3.1 General In addition to message deposit, the following facilities may be made available: — multi-address*; — follow-on messages*; — positive delivery notification; — status enquiry request; — message cancel request*. Note — The multi-address facility would not normally be available to incoming international telex calls except by bilateral agreement. 3.2 Message deposit 3.2.1 Validation of format and/or length should preferably be performed by the FAXIWF on the address(es) of the called fax terminal(s) as specified by the calling party. 3.2.2 Where the multi-address facility is provided, the FAXIWF should be capable of accepting at least 20 facsimile terminal (PSTN) addresses in a multi-address call. PAGE6 styleref head_footRecommendation F.87 3.2.3 An attention information field facility should be provided by the FAXIWF to enable each addressee of a multi-address message to have a relevant attention prefix preceding the message in the header page where such is provided. 3.2.4 A message reference number shall be available to the calling party for every message accepted by the FAXIWF. For multi-address messages, a separate message reference number may be provided for each address. 3.2.5 The application of short-code address* and pre-recorded address lists is a national matter. 3.3 Follow-on messages Provision may be made to accept follow-on message(s) with their associated address(es) which may be sent immediately after the deposit of a previous message while still retaining the connection to the FAXIWF from the originator. The procedures should be aligned with Recommendation U.43. 3.4 Status enquiry request 3.4.1 Status information on previously-deposited message shall only be returned to the message originator. The procedure used should be generally aligned with Recommendations F.72 and U.80. 3.4.2 This status information should be available for at least 24 hours after the time of message receipt by the FAXIWF. 3.5 Message cancel request* If message cancellation is provided, previously deposited messages may only be cancelled by the message originator. 3.6 Delivery/non-delivery notification message and journals 3.6.1 In the case of failure to deliver a message to the requested fax terminal, the FAXIWF shall if possible return a non-delivery notification message to the originator (see S 7.1). 3.6.2 An Administration may optionally provide a positive delivery notification message to the originator upon successful delivery of the message to the requested fax terminal (see S 7.2). 3.6.3 The above notifications may also be provided in a summarized form (journals). 4 Access procedures 4.1 General Two basic procedures for access from a telex terminal should be provided by the FAXIWF: a) Interactive operation: — input from manual calling terminals where the TPIWF may return prompt signals; b) Non-interactive operation: — input from telex automatic emitting devices where prompt signals may not be required; — interworking with other types of interworking and conversion facilities. 4.2 One-stage selection In the one-stage selection procedure, the facsimile terminal is assigned a telex number that is part of the national telex numbering plan. styleref head_footRecommendation F.87PAGE 7 4.2.1 Call establishment 4.2.1.1 The originator (or intermediary interworking or conversion facility) shall use normal telex procedures. 4.2.1.2 The telex number received by the FAXIWF shall be verified as being proper to a registered facsimile terminal. The method of effecting this verification is a national matter. If the verification fails, the following procedures should be applied: a) where the FAXIWF is provided by the Administration which also provides all or part of the telex network, the service signal NP may be returned; b) where the FAXIWF is not provided by the Administration which also provides all or part of the telex network, the procedures to be applied shall be in accordance with Recommendation F.74. 4.2.1.3 Having verified the received telex number, the FAXIWF shall return the answerback allocated to the requested facsimile terminal to the originator. 4.2.1.4 This answerback of the facsimile terminal shall be formatted in accordance with Recommendation F.74. 4.2.1.5 In accordance with Recommendation S.23, the FAXIWF may transmit a WRU signal to the originating telex subscriber if the backward path remains idle for at least 800 milliseconds. 4.2.1.6 Having received the answerback allocated to the called facsimile terminal, the originator may input the text of his message. The FAXIWF shall respond to any received WRU signal during this phase of the call by returning the answerback allocated to the facsimile terminal. 4.2.1.7 The reaction to abnormal conditions during call set-up shall be in accordance with normal telex procedures (see Recommendation U.2071) ). 4.3 Two-stage selection 4.3.1 General 4.3.1.1 Calls to the FAXIWF will be established by means of normal telex procedures. 4.3.1.2 The received telex answerback shall be processed in accordance with Recommendation U.74 to determine the calling telex address. If the answerback is deemed to be non-processable, the FAXIWF shall request input of the calling address by the telex subscriber by returning the ADD prompt. 4.3.1.3 Transmission from an automatic terminal is indicated by commencing the procedure with the non-interactive service request (characters CI). The calling terminal is recognized as interactive by the omission of the non-interactive service request (CI). 4.3.1.4 If the calling telex address is capable of being extracted from the received answerback, the FAXIWF shall return GA, unless a non-interactive service request has been made. 4.3.2 Input of address(es) 4.3.2.1 For each address required, the originator should transmit the sequence FAX
+ (