1、ITU-T RECflN*U-204 93 W 4862591 0594243 408 W INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOM MUN KATION STAN DARD IZATION SECTOR OF ITU TELEGRAPH SWITCHING INTERNATIONAL TELEX SERVICE U.204 (03193) INTERWORKING BETWEEN THE INTERNATIONAL TELEX SERVICE AND THE PUBLIC INTERPERSONAL MESSAGING SERVI
2、CE ITU-T Recommendation U.204 (Previously “CCITT Recommendation”) 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 tariff questions and issuing Recomme
3、ndations 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 Recommendations on these topics
4、. ITU-T Recommendation U.204 was revised 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 the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its pl
5、ace, 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 Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.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 change has been made in the text to
6、 references containing the acronyms “CCITT, CCIR or IFRi3” 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 administration and a recognized operati
7、ng 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 photocopying and microfilm, without
8、 permission in writing from the ITU. ITU-T RECMNbU.204 93 W 4862593 0594245 280 W CONTENTS Introduction 1.1 Scope 1.2 Service outline Methods of interworking Telex access to the IPM service . 3.1 One-stage selection . 3.2 Two-stage selection . 3.3 IPM elements of service in the telex to IPM directio
9、n . 3.4 Message desposit and format . 3.5 3.6 Follow-on call facility . Access from the IPM service to telex . Telex message delivery inside the IPM service . 4.1 General principles 4.2 Conversion 4.3 Message delivery to telex . Notification messages . 5.1 Delivery notification . 5.2 Non-delivery no
10、tification 5.3 Combined delivery and non-delivery notifications . Clearing procedures . Abnormal conditions . . 7.1 Telex-to-IPMS direction . 7.2 IPMS-to-telex direction Annex A . 1) Example of message : Telex-to-IPM service . 2) Example of message : IPM service-to-telex References . Recommendation
11、U.204 (03/93) Page 2 2 2 3 3 3 5 10 11 12 12 12 12 12 12 14 14 15 18 18 19 19 20 21 22 23 1 ITU-T RECMN*U-204 93 4862593 0594246 317 Recommendation U.204 INTERWORKING BETWEEN THE INTERNATIONAL TELEX SERVICE AND THE PUBLIC INTERPERSONAL MESSAGING SERVICE) (Melbourne, 1988; revised Helsinki, 1993) The
12、 CCITT, considering (a) (b) the telex service: (c) messaging system; (d) (e) (0 (g) that Recommendation F.421 defines the operational procedures for interworking between the public interpersonal messaging service and the telex service: (h) (i that Administrations are introducing public message handl
13、ing services; that there are benefits in the provision of an interworking capability between message handling services and that there are already existing arrangements in place for interworking between telex and the interpersonal that Recommendation F.60 defines the operational provisions of the int
14、ernational telex service; that the F.400-Series Recommendations define the service requirements of the message handling services; that Recommendation F.420 defines the service requirements of the public interpersonal messaging service; that the U-Series of Recommendations define the technical requir
15、ements of the telex service; that the X.400-Series Recommendations define the technical requirements of the message handling services, unanimously declares that, for new implementations, the technical aspects of interworking between the telex service and the public interpersonal messaging service sh
16、all be in accordance with this Recommendation. Definitions The following terms used in this Recommendation have the undermentioned definitions: PTLXAU: The public telex access unit (PTLXAU) is a functional unit which implements the requirements to allow the delivery of messages from telex subscriber
17、s to users of the interpersonal messaging service (and vice versa) as specified in the relevant U-Series and X-Series of Recommendations. The method of implementation of these functions in any physical unit is a national matter. registered IPMS user: A user of the interpersonal messaging service who
18、 has registered with the PTLXAU for the receipt of telex messages and who is assigned a telex number that is part of the telex national numbering plan for this purpose. IPMS user answerback: In the case of one-stage selection, the answerback that is returned to the telex network on receipt of a WRU
19、signal and which uniquely identifies the registered IPM user to the telex network. ) Throughout this Recommendation, the term “telex” should be interpreted as referring exclusively to “the international telex service”, as described in Recommendations F.59 and F.60. Recommendation U.204 (03/93) 1 FTL
20、XAU answerback: In the case of two-stage selection. the answerback of the destination FTLXAL and which is always returned by the FTLXAU in response to a received WRU signal. FTLXAU identification: When delivering an IP message to a telex subscriber. the sequence transmitted by the PTLXAU which indic
21、ates the country of origin of the PTLXAU and IPM service. 1 Introduction 1.1 Scope 1.1.1 the public interpersonal messaging service (IPMS). This Recommendation defines the procedures to be followed for interworking between the telex service and 1.1.2 Recommendation F.42 i i J. The operational proced
22、ures of this interworking capability and the full range of facilities are described in 1.1.3 For calls originated in either service, communication will be affected using the international telex network. 1.2 Service outline 1.2.1 conversational-mode interworking is thus not applicable. Communication
23、between subscribers of the telex service and the IPM service is on a store-and-forward basis; 1.2.2 Delivery of messages from telex subscribers to users of the IPM service as well as delivery of messages to the international telex network from IPMS users shall be provided by means of a public telex
24、access unit (FTLXAU) which shall be considered as part of the IPM service. 1.2.3 international telex network, as shown in Figure 1. For calls originated by either telex subscribers or IPMS users, the international connection shall be via the I I Country A internationai telex i Service i I i i I I I
25、Countty B I PM Shce TO901 550-94/601 FiGURE iAJ.204 Basic model For interworking between the international telex service and the public interpersoiial messaging service 2 Recommendation U.204 (03193) ITU-T RECMN*U=204 93 m 4862593 0594248 T9T m 1.2.4 selection. The procedures to be followed by an or
26、iginating telex subscriber allow for either one-stage or two-stage 1.2.5 and addressing in the message handling services are found in Recommendation F.401 2. The IPMS user will follow normal MHS addressing principies when sending to telex. The rules for naming 2 Methods of interworking considering a
27、) that different addressing formats may be used within the IPM service; b) that these formats may consist of either numeric or mnemonic information, then the following methods of interworking between the telex service and the IPMS may be provided: 1) interworking with one-stage selection, 2) interwo
28、rking with two-stage selection. Messages from an IPM service user are sent as normal IP messages using the appropriate elements of service in accordance with Recommendation F.420 8. 3 Telex access to the IPM service 3.1 One-stage selection In the one-stage selection procedures, the IPM service user
29、is assigned a telex number that is derived from the national telex numbering plan. Figure 2 shows the recommended access procedures. 3.1.1 Call establishment 3.1.1.1 The originating telex subscriber will select the IPM service user using normal telex procedures. 3.1.1.2 matter. The procedures for ca
30、ll establishment between the terminating telex network and the PTLXAU are a national 3.1.1.3 The telex number received by the PTLXAU from the telex network will be verified by the IPM service as being proper to a registered IPMS user. The method of effecting this verification is a national matter. I
31、f the verification fails, the procedures to be adopted shall be in accordance with Recommendation F.421 i. 3.1.1.4 the originating telex subscriber using normal telex signalling procedures. If the submitted telex number is positively verified, then the PTLXAU shall return the call connected signal t
32、o 3.1.1.5 network shall conform to Recommendation F.74 3. The IPM service user answerback returned by the PTLXAU in response to the WRU signal from the telex 3.1.1.6 commencing the procedure with the non-interactive service request (CI). If the call originates from a telex automatic emitting device,
33、 the calling telex subscriber should indicate this by 3.1.2 Determination of the calling telex address 3.1.2.1 Following the transmission of the IPMS user answerback, the PTLXAU shall monitor for the receipt of characters from the telex network and shall transmit a WRU signal only after an idle cond
34、ition has existed for at least 800 ms. 3.1.2.2 the rules laid down in Recommendation U.74 141. The PTLXAU shall determine the calling telex address from the received telex answerback in accordance with Recommendation U.204 (03/93) 3 3.1.2.3 The PTLXAU shall wait 3 seconds from the end of the calling
35、 telex answerback to enable the telex subscriber to input the calling telex address. At the end of this period and if the calling telex address cannot be determined from the received telex answerback, then the PLXAU shall return the prompt signal. 3.1.2.4 If the calling telex address is not received
36、 within 15 seconds of the ADD prompt, then another prompt signal shall be returned. If another 15 seconds elapse without the receipt of the calling telex address, the connection shall be - cleared by the PTLXAU. PTLXAU Telex Side IPMS Side NOTES 1 These procedures are a national matter. 2 In accorda
37、nce with Recommendation S.23. this WRU signal may be transmitted 800 ms after the transmission of the IPM user answerback if the backward path remains idle. 3 The ADD prompt is only sent if the return telex address cannnot be determined 60m the received telex answerback (see 3.1.2). The calling tele
38、x address may be preceded by a CI signal to indicate an automatic terminal. The CI may precede the calling telex address as voluntarily submitted by the caller without any WU AU-generated prompts, as follows: a) ADD (com PTLXAU) CI 50032266 OT b) CI ADD 50032266 4 receipt of the calling telex addres
39、s. GA signal is sent if text input has not commenced within 3 seconds of the FIGURE 2KJ.204 Cd1 set-up in the telex-to-IPM direction (case of one-stage selection) 4 Recommendation U.204 (03D3) 3.1.2.5 The calling telex address shall be input by the telex subscriber in the following format: t - F.69
40、code national telex number t - t = - e.g. ADD 50032266 The calling telex address may optionally be preceded by ADD. 3.1.2.6 The calling telex address, when received, may be preceded by the non-interactive service request CI, which may or may not be associated with carriage-return, line-feed and lett
41、er-shift characters. In this case, the call procedure originating from a telex automatic emitting device will be as shown in Figure 3. FIGURE 3AJ.204 One-stage access from telex to IPMS (case of telex automatic emtting device) 3.2 Two-stage selection The two-stage selection, the address(es) of the I
42、PMS user(s) is/are given prior to the transmission of the message and after a telex connection has been established between the originating telex subscriber and the gateway to the IPM service, i.e. the PTLXAU. The use of either upper- or lower-case letters by the originating telex subscriber in the
43、input of service identifiers, address attributes, etc., has no significance. Recommendation U.204 (03/93) 5 ITU-T RECMN*U.204 93 m 4862593 0594253 584 m 3.2.1 The originating telex subscriber will use normal telex procedures to access the PTLXAU which will be allocated a telex number that is derived
44、 fi-om the national telex numbering plan of the country in which the PTLXAU is located. The PTLXAM answerback shall be formatted in accordance with Recommendation F.60 optionally preceded by the code expression CI (4.3.3). 3.2.2 in this Recommendation and are shown in Figure 4. The procedures to be
45、followed shall be in accordance with Recommendation U.80 5, except where specified I I I I FIGURE W.2M Telex access procedures to P“LXAU using twwstage selection (applicable to either manual terminal or TAED) Notes to Figure 4 1 answerback if the backward path remains idle. In accordance with Recomm
46、endation S.23, this WRU signal is transmitted 800 ms after transmission of the RLXAU 2 One additional WRU signal shall be transmitted by the PTLXAU if: a) b) there was no response to the first WRU, or signals were received after the first WRU which could not be identified as an answerback. This seco
47、nd WRU should be transmitted at least 10 seconds after the transmission of the first WRU and only after a period of 300 ms of idle condition has been detected. 3 Case A: Procedure to be followed when the calling telex address can be determined from the received telex answerback. 4 Case B: Procedure
48、to be followed when the calling telex address cannot be determined from the received telex answerback. 6 Recornmendation U.24 (03/93) ITU-T RECMN*U.204 93 4Bh259L 0594252 410 5 In Case A, the prompt GA shall be transmitted 3 seconds after detection of the processable answerback. In Case B, the promp
49、t GA shall normally be transmitted 3 seconds after receipt of the calling telex address. 6 The prompt ADD is used only in Case B and is sent when a non-processable answerback has been detected and if the calling telex subscriber has not voluntarily input the proper calling telex address. The procedures to be followed shall be in accordance with 3.1.2.4 and 3.1.2.5. 7 8 9 IO 11 The service request CI is usually sent when the calling telex terminal is operating in a non-interactive mode. The procedures to be followed shall be in accordance with 3.1.2.4 and 3.1.2.5. The
