1、 ITU-T RECMN*U.207 93 m 4862593 0588833 942 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEGRAPH SWITCHING INTERNATIONAL TELEX SERVICE U.207 (03/93) TECHNICAL REQUIREMENTS TO BE MET FOR THE TRANSFER OF MESSAGES BETWEEN TERMINALS OF THE INTERNATIONAL
2、 TELEX SERVICE AND GROUP 3 FACSIMILE TERMINALS CONNECTED TO THE PSTN ITU-T Recommendation U.207 (Previously “CCITT Recommendation”) ITU-T RECMN*U.207 93 48b2591 0588832 889 W FOREWORD The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom- municati
3、on Union. The ITU-T 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 World Telecommunication Standardization Conference (WTSC), which meets every four years, established
4、 the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. ITU-T Recommendation U.207 was prepared by the ITU-T Study Group IX (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within
5、 the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the IT 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 Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunicat
6、ion Sector. In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms ?CCITT, CCIR or IFRB? or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the prope
7、r terminology related to the new ITU structure. 2 telecommunication administration 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 ut
8、ilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. _ ITU-T RECMN*U.207 93 = 48b259L 0588833 715 CONTENTS Page 1 Introduction 1 2 Basic interworking service . 1 3 Interworking in the telex to facsimile direct
9、ion . 2 4 Notifications 7 5 Interworking in the facsimile-to-telex direction . 7 Annex A - Reactions to abnormal conditions during text input from telex . 8 . Recommendation U.207 (03/93) I ITU-T RECMNUU-207 93 = 4862571 0588834 651 Recommendation U.207 TECHNICAL REQUIREMENTS TO BE MET FOR THE TRANS
10、FER OF MESSAGES BETWEEN TERMINALS OF THE INTERNATIONAL TELEX SERVICE AND GROUP 3 FACSIMILE TERMINALS CONNECTED TO THE PSTN (Helsinki, 1993) 1 Introduction This Recommendation defines the technical requirements to be met for the transfer of messages between terminals of the international telex servic
11、e and Group 3 facsimile terminals connected to the public switched telephone network. Interworking with Group 4 facsimile terminals is for further study. 2 Basic interworking service 2.1 Message transfer shall be provided on a store-and-forward basis via the FAXIWF. 2.2 devices (TAEDs). The interwor
12、king shall be established by provision of a Telefiacsimile Interworking Facility (FAXIWF). The FAXIWF shall cater for access from both manual operated telex terminals and telex automatic emitting 2.3 In the telex to facsimile direction the following functions shall be provided by the FAXIWF: - accep
13、tance of messages from the telex side, with accompanying addressing information, - division of the text received into pages and preparation of a “Header Page” (or a herald), containing all necessary recall information, for delivery to the facsimile side, delivery of these messages immediately after
14、complete reception to the requested facsimile terminal, with retries if necessary, - - provision of non-delivery notifications. In addition to the basic functions the following facilities may be provided: - 2.4 multi-address (not applicable in one-stage access method). This facility shall be barred
15、for international access, except if a bilateral agreement exists between the Administration of the caller and the provider of the FAXIWF. Where this facility is provided, the FAXIWF should be capable of accepting at least 20 fac- simile terminal (PSTN) addresses in a multi-address call; follow-on me
16、ssages (not applicable in one-stage access method); message cancellation during text input. Request for message cancellation shall be indicated by the caller by an FFFF sequence. As response, the FAXIWF shall send the sequence ANUL ANUL; - - - positive delivery notification; - - - enquiry, e.g. for
17、status or cancel as defined in Recommendation U.220; attention information as in Recommendation U.80; short code selection and pre-recorded address lists as a national matter (not applicable in one-stage access method). 2.5 Types of interworking Interworking between the telex service and facsimile t
18、erminals consists of two directions: a) b) telex-to-facsimile. This is described in clause 3; facsirnile-to-telex. This is described in clause 5. Recommendation U.Un (03/93) 1 ITU-T RECMN*U.207 93 = 4862593 0588835 598 2.6 Access methods for the telex subscriber The following methods to access the F
19、AXIWF can be provided for the telex subscriber. However, all three methods are based on store-and-forward principles. a) b) c) one-stage selection. This method is described in 3.1; two-stage selection. This method is described in 3.2; via a store-and-forward unit. This method allows to mix addresses
20、 of different services (e.g. telex, Teletex, Videotex, . ) in a multi-address call and is described in Recommendations U.80 and U.200. The service requirements for methods a) and b) are described in Recommendation F.87. 2.7 Where a TPIWF in accordance to Recommendation U.203 is provided, provisions
21、can be made to allow Data Terminal Equipments (DTEs) connected on a Packet Switched Public Data Network (PSPDN) access to the telex side of a FAXIWF. 3 Interworking in the telex to facsimile direction 3.1 For a telex subscriber, the procedure to be followed is the same as for a normal telex call. Th
22、e telex subscriber shall, but is by no means forced to, transmit his answerback at the beginning and at the end of a call in accordance to Recommendation F.60. No distinction is necessary to identify a terminal to be manual or automatic (TAED). Figure 1 and the appending notes show the procedure in
23、detail. One-stage selection access to the Teleflacsimile Interworking Facility (FAXIWF) - To900661 -91/dO1 FIGURE 1AJ.207 Onestage seledian access toa TehdFacdndle Iderdng Faciiity (FAXIWF) 3.1.1 The total selection information (including the F.69 area code and a possible national prefix) for the fa
24、csimile user shall not consist of more than 12 digits. This requirement has normally the consequence to register each facsimile user who wants to communicate with telex subscribers and assign to him a telex number, different from his facsimile number. 3.1.2 Validation is done in the FAXW to get the
25、following information: Note 1 to Figure 1 Note 2 to Figure 1 - - if the selection corresponds to a registered facsimile user; status of the facsimile user (could be any not-ready condition on a registration basis). 2 Recommendation U.2W (0x93) ITU-T RECMN*U=20? 73 4862571 058883b 424 If the validati
26、on fails, the FAXIWF shall return the service signal NP and clear the call. In case the facsimile user is in a registered “not ready” condition, the FAXIWF shall return the appropriate service signal (in accordance with Recommendation U.45) to the calling telex subscriber and clear the call. 3.1.3 N
27、ote 3 to Figure 1 The answerback code of the facsimile user shall be in accordance to Recommendation F.74 and shall contain the complete national call number, including a possible prefix. The letterpart of the answerback may be registered in the FAXIWF, specific for each registered facsimile user. I
28、n case of no registration, “FAX shall be used as letterpart for all answerbacks. 3.1.4 After provision of the answerback the link shall be transparent to the caller. See Annex A (abnormal conditions) for the reaction of the FAXIWF to characters or character strings which are not possible to be displ
29、ayed on a facsimile terminal. Note 4 to Figure 1 3.1.5 Note 5 to Figure 1 A WRU signal received from the telex subscriber in any stage of the message input causes the FAXIWF to return the answerback of the facsimile user as described in 3.1.3. 3.2 Two-stage selection access to the TeledFacsimile Int
30、erworking Facility (FAXIWF) Interworking in the telex-to-facsimile direction, using two-stage selection, is described in Figure 2 and the appending notes. Call (Note 1) FAXIWF answerback (Note 21 ITD (Noie 91 1 Clearing I F A X I W F Validation (Note 6) FIGURE 2NJ.207 Twestage selection access to a
31、TeledFacsime interworking Facility (FAXWF) 3.2.1 Normal telex procedures apply for the telex subscriber to set up the call to the FAXIWF. Note 1 to Figure 2 Recommendation U.2W (03/93) 3 ITU-T RECMN*U.207 93 4862593 0588837 3b0 3.2.2 Note 2 to Figure 2 Coding of the FAXIWF answerback is the followin
32、g: “Figs”, “CR, “LF, FAXIWF National Number, “Lttrs”. “SP, FAXIWF, “SP”, O O means the TNIC, e.g. “A” for Austria To be filled with “Lttrs” according to Recommendation F.60. Example: 760000 faxiwf a 3.2.3 Note 3 to Figure 2 The telex subscriber can send his answerback in this stage of the procedure.
33、 This shall always be the case if a Telex Automatic Emitting Device (TAED) is in use. In the TAED case, the answerback shall be followed by a CI sequence. 3.2.4 Note 4 to Figure 2 A WRU may be sent in accordance with Recommendation S.23 to the caller to get his answerback. This answerback will be ev
34、aluated in accordance with Recommendation U.74. In case of a manual terminal and if the telex address cannot be found on the basis of this answerback, the FAXIWF shall send an “ADD prompt to the caller to get the calling telex address. In response to the “ADD prompt the caller shall provide his tele
35、x address in the form: “Figs”, Telexaddress, “CR, “LF, “CR, “LF The telex address may be preceded by “ADD. The telex address has to consist of the F.69 code and the national number. The FAXIWF may validate the telex address, e.g. for valid F.69 code and number length. In case the calling terminal is
36、 a TAED the answerback should have been provided by the caller as described in 3.2.3. The telex address, if not extracted from the answerback should have been provided by the caller at the address input as described in 3.2.5.2. If the telex subscriber does not provide his telex address within 15 sec
37、onds, the FAXIWF shall send another ADD prompt. If the telex subscriber fails again to input his telex address the FAXIWF shall clear the call. The answerback and the telex address of the telex subscriber shall be included in the header page (or the herald) which is to be transmitted to the called f
38、acsimile terminal. 3.2.5 Note 5 to Figure 2 The facsimile address is generally the E.164 address of the facsimile terminal and may be (optional for the caller) preceded by the service identifier “FAX”. If selection input does not commence within three seconds, the FAXIWF shall return the service cod
39、e GA. The selection shall be delimited from the message by the End of Address sequence “BT” Where the FAXIWF offers an (optional) Positive Delivery Notification (FDN), the caller may request this PDN by terminating the relevant address line by, ACK. See the following examples. The selection can have
40、 one of the following formats: 3.2.5.1 “CR”, “LF, “Figs”, Facsimile address, +, “CR”, “LF, “Lttrs”, BT This format is normally used by a manual operated telex terminal, allowing the FAXIWF to send prompts. Example: 43150i45207+ BT 4 Recommendation U.207 (03/93) - ITU-T RECMN*U*207 93 = 48b259L 05888
41、38 2T7 3.2.5.2 “CR”, “LF, “LTTRS”, CI, “CR”, “LF, ADD, “Figs”, telex address, “CR”, “LF, “CR”, “LF, %igs”, facsimile address, +, “CRY?, “LJ?, “Lttrs?, BT Telex address is the callers own telex address consisting of the F.69 code and the national number. In case the caller has an answerback which is
42、processable in accordance with Recommendation U.74 and provided the answerback already (see 3.2.3), input of the telex address can be omitted. When the caller did not provide his telex address and his answerback is not processable in accordance with Recommendation U.74, the FAXIWF shall clear the ca
43、ll. This format is normally used by a Telex Automatic Emitting Device (TAED). In this case the FAXIWF is not allowed to send prompts. Examples: a) CI ADD42609600 43150145207+ BT b) CI 353 1778800+,ACK BT 3.2.5.3 Where muiti-address is provided, all single addresses shall start on a new line and shal
44、l be terminated with the End of Address sign “+” Examples: a) 43150145207+ (zu handen herrn berger) 43250260+ 33130731660+ ( lattention de m. prost), ACK BT b) CI ADD47 10050 33130731660+ 441 880025+(attention mr mansell), ACK 4978 122273+ BT 3.2.6 As an option, a data base validation can be done, e
45、.g. on the number length, significant digits, correct Telephone Country Code, . . If the validation result is negative, the FAXWF shall stop the message input by sending a sequence of “TTT.” characters, followed by a “NF” service signal. Note 6 tcr Figure 2 3.2.7 As described in A.6 a “GA” shall be
46、sent to the telex subscriber if he does not start message input within 30 seconds. Note 7 to Figure 2 See Annex A (abnormal conditions) for the reaction of the FAXIWF to characters or character strings which are not possible to be displayed on a facsimile terminal. 3.2.8 In case of a follow-on-messa
47、ge the telex subscriber shall use four combinations No. 14 (NNNN) as End Of Message (EOM) indicator. This allows him to input the next message, starting with the called address (as described in 3.2.5), immediately. Alternatively, the telex subscriber may use the sequence NNNNACK. This causes the FAX
48、IWF to acknowledge those messages not previously acknowledged and provide an IMA. containing: Note 8 to Figure 2 - The text “IMA” - Date and Time - The message reference numbeds) Recommendation U.207 (03/93) 5 ITU-T RECMN+U.207 93 D 4862593 0588839 133 After the last (or only one) call in one sessio
49、n the telex subscriber shall send a sequence of four combinations No. 26 (+) which is considered by the FAXIWF as End Of Transaction (EOT). If a calling telex subscriber does not send an EOT sequence (this is the normal case for a TAED), the message shall be accepted as complete and forwarded as received. 3.2.9 Note 9 to Figure 2 After reception of the EOT, an ITD as described in Recommendation U.80 shall be sent to the telex subscriber by the FAXIWF. 3.3 Delivery to facsimile terminals 3.3.1 After complete reception of a message from the telex side, the
