1、CCITT RECMN*F.420 92 48b259L 0574574 T28 INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE MESSAGE HANDLING SERVICE OPERATIONS AND DEFINITION OF SERVICE F.420 (08/92) MESSAGE HANDLING SERVICES: THE PUBLIC INTERPERSONAL MESSAGING SERVICE Reco
2、mmendation F.420 CCITT RECMN*F=420 92 M 4862593 0574575 964 FOREWORD The CC (the Intemational Telegraph and Telephone Consultative Committee) is a permanent organ of the Intemationai Telecommunication Union (IT). CCT is responsible for studying technical, operating and tariff questions and issuing R
3、ecommendations on them with a view to standardizing telecommunications on a worldwide basis. The Plenary Assembly of CClT which meets every four years, estabiishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT
4、between Plenary Assemblies is covered by the procedure laid down in CC Resolution No. 2 (Melbourne, 1988). Recommendation F.420 was revised by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. CCIIT NOTES 1) telecommunication Administration and a recogniz
5、ed private. operating agency. 2) In this Recommendation, the expression “Adminisrration” is used for conciseness to indicate both a A list of abbreviations used in this Recommendation can be found in Annex A. O ITU 1993 All rights reserved. No part of this publication may be reproduced or utilized i
6、n any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. CCITT RECNN4cF.420 92 W 4862591 0.574576 8TO Purpose and scope Il Recommendation F.420 I 1.1 General MESSAGE HANDLING SERVICES: THE PUBLIC INTERPERSONAL MESSAGING S
7、ERVICE The Interpersonal Messaging (IPM) service enables subscribers to request a variety of features to be performed dwing the handling and exchange of messages. (revise4 1992) The establishment in various countries of message handling services in don with public networks creates the need to produc
8、e Recommendations covering the aspects of public message handling services. CONTENTS 1 Purposeand scope 2 IPM service 3 Types of body parts 4 5 6 peration of the service 7 Quality of service 8 Tariff and accounting principles 9 Network requirements 10 User information and support 11 AnnexA - Abbrevi
9、ations Annex B - Subscriber access and terminal requirements Appendk I - Errata to Recommendations F.421 and F.422 Conversion between different encoded information types Naming and addressing in general Use of the IPM service within CC-defined telematic services This Recommendation specifies the gen
10、eral, operational and quality of service aspects of the public international Interpenonal Messaging service. Interpersonal messaging services provided by Administrations belong to the group of telematic services defined in the F-Series Recommendations. This type of Message Handling service is an int
11、ernational telecommunication service offered by Administrations, enabling subscribers to send a message to one or more recipients and to receive messages via telecommunication networks using a combination of storeand-forward, and store-and-retrieve techniques. Locally provided functions, for which c
12、ommunication with other subscribers is not required, are not covered by CCI“ Recommendations. Recommendation PAN (O92) 1 CCITT RECMN*F-420 92 m 48b25L 0574577 737 Some features are inherent in the bask IPM service. other non-basic features may be selected by the subscriber, either on a per-message b
13、asis or for an agreed contractual period of time, if they are provided by Administrations. Basic features bave to be made available internationally by Administrations. Non-basic features, visible to the subscriber, are classified as either essential or additional. Essential optional features must be
14、 made available internationally by Adminisirations. Additional optionai features may be made available by some Administrations for national use and internationally on the basis of bilaterai agreement. Non-basic features are called optional user facilities. IPM service may be provided using any physi
15、cal network. IPM service may be offered separately or in combination with various telematic or data communication services. It can be obtained by making appropriate arrangements. Recommendations, in Recommendation T.330 and in Recommendation U.204. Technical specifications and protocols, to be used
16、in the IPM service, are defined in the X.400-Series This service however, a later audit must be possible. When an ADMD interacts with a PRMD, the ADMD takes responsibility for the adions of the PRMD which are related to the interaction. In addition to ensuring that the PRMD properly provides the MT
17、service, the ADMD is responsible for ensuring that the accounting, logging, quality of service and other related operations of the PRMD are correctly performed. An ADMD acts as the naming authority for the associated PRMDs. 2.4 Message store Administrations may optionally provide MS to permit delive
18、ry of messages so that the recipients UA does not have to be on line continuously. This is described in Recommendation F.400,d 7.4. A message delivered to an MS is deemed delivered by MHS. Messages delivered to an MS can be retrieved by the recipient at his Convenience and various optional user faci
19、lities can be provided to aiiow for retrieval for listing, fetching, and deletion of messages. When subscribing to an MS, ail messages destined to the UA are delivered to the MS, and if he UA is on line, an aiert will be sent to the UA (from the MS) to inform the user of the fact that a message just
20、 arrived. 2.5 Use of directory By making use of directory systems, IPM users wiil be able to address recipients by using directory names or distribution list names, which are more user friendly than originator/recipient (OR) addresses. The MHS wiii be able to access a directory system and find out t
21、he OR address) corresponding to a given direwry name or distribution list name, for delivery of a message. mis capability is described in Recommendation F.400,s 14. 2.6 Security Administrations may optionally provide security mechanisms as outiined in Recommendation F.400,$15, to counter the various
22、 security threats mentioned. This capabiity relies on a directory system storing certified copies of public keys for MHS users. 2.7 Distribution lists A group whose membership is store in the directory can be used as a distribution list L). The originator simply supplies the name of the list on subm
23、ission of a message, and the MHS can obtain the directory names (and then the OR addresses) of the individual recipients, by consulting the directory. Upon receipt of a message addressed to a distribution list, the recipient can determine through which DL the message arrived. An originator can prohi
24、bit the expansion of the distribution if one of the recipients specifmi refers to a distribution list. Recommendation F.400, 8 14, outlines the full capabilities available to DL users. Recommendation FAU) (08192) 5 CCITT RECNNrF.420 92 m 4862591 0574583 168 if a user unknowingly sends a message to a
25、 DL, he may incur charges for multiple deliveries that he was not expecting. Because of this, names of distribution lists should be indicative of the fact that what is being named is a DL. Owners of DLs should also msure that they respect a potential members wishes about being a member and the rules
26、 of the country of the member that may prohibit inclusion without prior agreement. 2.8 intercommunication with physical delivery services The intercommunication with the physical delivery (PD) services is an optional capability of the IPM service that allows for the sending of a message from an IPM
27、user to a recipient via physical means, such as the traditional postal service. To invoke the capability, the originating user shall use the requested delivery method element of service on submission of his message, speafymg physical delivery. The message may be addressed using the postal OR addre-s
28、s, or the directgr name of the intended recipient, in which case the MHS will consult the directory system to determioe the postal O/R address, The use of MWPD service intercommunication by IPM users is described in Recommendation F.415 and Recammendation F.400,8 10. 3 Types of body parts Messages s
29、ent and received in the IPM service can be composed of one or more body parts. Applicable body part types are defmed in Recommendation X.420 and comprise the following: - - voice, - Group 3 (G3) facsimile, international Alphabet No. 5 (IAS) text, facsimiie, - Group 4 (G4) class - teletex, - videotex
30、, - encrypted - - mixedmode, - bhtedlydefined, message (e.g. for a forwarded message), - natidydefined, - extemailydefined, - generaltext, - filetransfer. 4 Conversion between different encoded information types The MTS provides conversion functions to aliow IPM users to input messages in one encode
31、d format, called encoded infomation type 0, and have them delivered in another EIT to cater to users with different terminal types. This capability is inherent in the IPM service, and increases the possibility of delivery by tadoring the message to the recipiits terminal capabiiliiies. The ERS suppo
32、rted for the IPM service are - delivery notification; - receipt notification; - non-receipt notification. Non-delivery notification and delivery notification (if requested) are automatically generated by the MTS, while receipt and non-receipt notification depend on the action of the recipient UNreci
33、pient. 7 Quality of Service 7.1 Message status The unique identification of each IP-message enables the system to provide information about, e.g., the status of an IP-message. In the event of system failure, ail accepted and non-delivered messages should be traceable. If messages cannot be delivered
34、, the originator must be informed by a non-delivery notification. 7.2 Support by Administrations Administrations should provide assistance to their subscribers, with regard to non-delivery notifications not being received in due time, as far as public system components are concerned. Additional prov
35、ision on support of status and tracing of messages may be provided under national responsibility. When the user agent is provided by an Administration, additional functionality should be provided in order to minimize cases of not reading messages within a certain period of time (the definition of th
36、is period is for further study). This functionality could be, for example, alert messages sent to an automatic reception terminal. 7.3 Model of delivery and notcation times See Figure 1F.420. 7.4 Message delivery time targets The management domain of the recipient UA should force non-delivery notifi
37、cation if the message has not been delivered before x hours after submission (or after date and time indicated for deferred delivery), the value of x being dependent on the grade of delivery requested by the originator. (See Recommendation F.410, 4.4.) Recommendation F.420 (OW2) 9 CCITT RECMN*Fm420
38、92 4862593 0574585 803 MTA MTA creation of message Submission of message Transfer 1 of message Delivery of message I Notification generation ICI Notification delivery Reading of message Receipt notification Receipt notification m0277w2 Receipt notibation For more details, see Recommendation F. 410.
39、TI Deliverytime T2 Delivery notification time T3 Receipt notification time Note 1 - Stadng time of T3 conesponds to the time the message is displayed to the user and and Receipt Notification is actioned by the user. Note 2 -Ending time of T3 is tk. time that the Reipt Notification is made available
40、to the user through the UA or MS. Note 3 -Similar considerations apply to Non-receipt Notifications. 7.5 Delivety notijcation time targets Non-delivery notifications or requested delivery notifications should be returned on a per-recipient basis, in order not to delay notifications for those message
41、s in a multi-addressed message which have aiready been delivered, to enable the originating management domain either to rem per-recipient notificatons or to batch notifications to its subscribers. (See Recommendation F.410,O 4.5.) 7.6 Receipt notifications and non-receipt notijications Non-receipt n
42、oificatims are generated automatidy by the receiving UA. 10 RecommendatSon F.42 (OW) CCITT RECMN*F*420 72 m 4862573 057458b 74T m Grade of delivery (of the referred message) Time targets for receipt notifications in the first place depend on local arrangements. When receipt notifications or non-rece
43、ipt notifications are initiated by the receiving UAluser, they have the same time targets as the messages that cause them to occur (see Table 1F.420). 95% delivered within TABLE llF.420 Urgent Nomai Non-urgent 0.25 hours 1.0 hour 4.0 hours Note - It is expected that PWs will abide by these notificat
44、ion time targets. 7.7 Error protection Error protection on transmission is provided by the MHS and underlying protocols used in the provision of the IPM service. 7.8 Availability of service In principle, the IPM service should be available continuously. The user agent should be available for submiss
45、ion or delivery continuously (unless hold for delivery is invoked). In cases where the UA is not available for delivery continuously, a message store should be used. 7.9 8 9 Minimum storage capacity The storage capacity of a user agent and message store shall be sufficient to provide a high grade of
46、 service. Note - This is for further study. Tariff and accounting principles See D-Series Recommendations, specificaily; D.35 - General charging principles in the international public message handling services and associated applications (1992) D.36 - General accounting principles applicable to mess
47、age handling services (1991). Nt- .vork requirements The IPM service is network independent, that is, the basic service and the essential optional user facilities are provided independently of the type of network used for service access. Additional optional user facilities chosen by an Administratio
48、n to offer may vary. Recommendation F.420 (OW2) 11 CCITT RECMN*F*420 92 4Bh259L 0574587 686 10 User information and support A directory shall be provided by each Administration for its domain. The directory can be hard copy or preferably electtonic form. The directory shall at least contain the foll
49、owing: a) how to use the directory and the service; b) list of OR addresses of subscribers belonging to the Administrations domah c) list of standardized abbreviations for OR address anributes; d) list of country and AdmiuiSttation management domain names reachable by the public IPM service. 11 Use of the IPM service within CC-deflned telematic services See relevant F-Sexies Recommendations. A ADMD DL E EIT G3 G4 IA5 IP IPM MD MH MHS MS MT MTA MTS N/A O/R ANNEXA (to Recommendation F.420) Alphabetleal Ust of abbreviations used in this Recommendation Addition
