1、STD-ITU-T RECMN F.471-ENGL 1997 48b2591 Ob38904 153 INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU F.471 (08/97) SERIES F: NON-TELEPHONE TELECOMMUNICATION SERVICES Message handling services Operational requirements for the interconnection of voice-mail st
2、ore-and-forward units ITU-T Recommendation F.471 (Previously CCIlT Recommendation) ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES TELEGRAPH SERVICE Operating methods for the international public telegram service The gentex network Message switching The international telemess
3、age service The international telex service Statistics and publications on international telegraph services Scheduled and leased communication services Phototelegraph service Mobile services and multidestination satellite services MOBILE SERVICE TELEMATIC SERVICES Public facsimile service Teletex se
4、rvice Videotex service F. 1-F. 109 F.l-F. 19 F. 20-F. 29 F.30-F.39 F.40-F.58 F.59-F.89 F.90-F.99 F. 100-F.104 F. 105-F. 109 F.llO-F.159 F.110-F.159 F. 160-F.399 F.160-F.199 F.200-F.299 F.300-F.349 General Drovisions for telematic services F.350-F.399 r MESSAGE HANDLMG SERVICES F.400-F.499 DIRECTORY
5、SERVICES DOCUMENT COMMUNICATION Document communication Programming communication interfaces DATA TRANSMISSION SERVICES AUDIOVISUAL SERVICES ISDN SERVICES UNIVERSAL PERSONAL TELECOMMUNICATION HMAN FACTORS F.500-F.549 F.550-F.599 F.550-F.579 F.580-F.599 F. 6WF. 699 F.700-F.799 F. 800-F. 849 F.850-F.89
6、9 F.900-F.999 11 For further details, please refer to TU-T List of Recommendations. ITU-T RECOMMENDATION F.471 OPERATIONAL REQUIREMENTS FOR THE INTERCONNECTION OF VOICE-MAIL STORE-AND-FORWARD UNITS Summary This Recommendation describes the general principles and operational aspects of the voice-mail
7、 store-and-forward service defined in Recommendation F.472 when operated and interconnected between service providers. It also addresses the elements of service offered by Voice-mail Store-and-Forward Units (Voice SFUS) to its direct user, a voice-mail system and between Voice SFs. This service is d
8、esigned to be implemented in conjunction with Recommendation F.472 which describes the voice-mail store-and-forward service. Source IT-T Recommendation F.471 was prepared by IT-T Study Group 7 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 9th of August 1997. Recommend
9、ation F.471 (08/97) i - STD-ITU-T RECMN F-Li71-ENGL 1997 W ib2571 b38707 9b2 m FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommuni- cations. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU.
10、 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, establishes the topi
11、cs for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview,
12、the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws atten
13、tion to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or ot
14、hers outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU hadhad not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not
15、represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1997 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 permiss
16、ion in writing from the ITU. ii Recommendation F.471 (08197) STD-ITU-T RECMN F.47L-ENGL LS77 W 48b257L Ob36708 8T7 R 1 2 3 4 5 6 7 8 9 CONTENTS Scope References Abbreviations . Definitions Introduction 5.1 Interaction between the VMS and its direct user 5.2 Interaction between a Voice SFU and its di
17、rect user (i.e. VMS) 5.3 Interaction between Voice SFUs 5.4 Interaction between a Voice SFU and direct users of other services Overview 6.1 Interconnection . 6.2 Technical requirements . 6.3 Accounting and settlement Interconnection requirements . 7.1 General 7.2 Information exchange . 7.3 Voice enc
18、oding . 7.4 Transit arrangements Service interworking principles . 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 Message addressing Message identification Classes of service Message deferral . Envelope . SuccessfuVunsuccessful message delivery notifications SuccessfuVunsuccessful message transfer notifications .
19、Voice coding encoding conversion . Quality of service . 9.1 Objectives . 9.2 Storage capacity 9.3 Observations on the quality of service 9.4 Duration of service . Page 1 .1 1 2 2 2 3 3 3 3 4 4 4 4 4 4 5 5 6 6 7 7 7 8 8 8 9 9 9 9 9 9 Recommendation F.471 (08/97) . 111 Recommendation F.471 OPERATIONAL
20、 REQUIREMENTS FOR THE INTERCONNECTION OF VOICE-MAIL STORE-AND-FORWARD UNITS (Geneva, 1997) 1 Scope This Recommendation describes the general principles and operational aspects of the voice-mail store-and-forward service defined in Recommendation F.472 when operated and interconnected between service
21、 providers. It also addresses the elements of service offered by Voice-mail Store-and-Forward Units (Voice SFs) to its direct user, a voice-mail system, and between Voice SFUs. This service is designed to be implemented in conjunction with Recommendation F.472 which describes the voice-mail store-an
22、d-forward service. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, onstitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recom- mendations and other references ar
23、e subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - IT-T Recommendat
24、ion F.472 (1997), Service and operational requirements of the voice-mail store-and-foward service. IT-T Recommendation F.400K.400 (1996), Message handling: System und service overview. CCITT Recommendation F.440 (1992), The voice messaging service. CCITT Recommendation X.440 (1992), Message handling
25、 systems: Voice messaging system. CCITT Recommendation G.721 (1990) (See ITU-T Recommendation G.726.) CCITT Recommendation G.726 (1992) (Has replaced former CCIT Recs. G.721 and G.723), 40, 32, 24, 16 kbith Adaptive DifSerential Pulse Code Modulation (ADPCM). IT-T Recommendation G.728 - Annex G (199
26、4), 16 kbith fucedpoint specification. IETF RFC ? - April 1997 - Voice Profile for Internet Mail (VPIM) - Version 2. - - - - - - - NOTE -This new reference is incomplete as the document is not yet published. It is expected to be published in April 1997 as an Internet Proposed Standard. At such time
27、as the additional reference information is known (RFC number and publication date) the TSB editor will be advised by the document editor. 3 Abbreviations This Recommendation uses the following abbreviations: A ADPCM B DEST Destination Voice SIW E EOS Element of Service IETF Internet Engineering Task
28、 Force Level 1 Level 1 notification Additional EOS (defined in 3.1E.472) Adaptive Differential Pulse Code Modulation Basic EOS (defined in 3.1E.472) Essential EOS (defined in 3.1E.472) Recommendation F.471 (08/97) 1 Levei 2 Level 2 notification ORIG Origination REC Reception SFU Store-and-Forward Un
29、it TRANS Transit voice SFU VM S - failure reason and diagnostic information. Class of message delivery Level 2 notifications support the services identified in Table 2, and convey the semantics of successful or unsuccessful transfer of responsibility for the message from the destination Voice SFU to
30、 the recipients voice-mail system. NOTE 2 -Depending on local implementation of this service, a Level 2 notification may indicate that the responsibility for the message was accepted by the voice-mail system or the message was delivered to the recipients mailbox at the destination voice-mail system.
31、 B B B.54R.400 B B A.20lF.400 B B A.2m.472 Table 1R.471- Level 1 notification service elements (Level 1) B Basic feature as defined in F.472. 7.3 Voice encoding To ensure compatibility between all Voice SFUS, the audio voice message is to be digitally encoded according to Recommendation G.726 which
32、defines 32 kbit/s ADPCM. However, other encodings may be used (e.g. Recommenda- tion G.728 LD-CELP) but conversion facilities to and from Recommendation G.726 must be provided as noted in 8.8. 7.4 Transit arrangements The use of transit service elements for message transfer is subject to agreement o
33、f the service providers involved. Transit EOS support classification is identified in Table 3 as a column titled “TRANS“. A voice message may pass through a transit facility consisting of a Voice SF or some other transfer system. Voice SFUs offering transit, redirection, distribution list expansion
34、or relay services shall support Level 1 notifications. Recommendation F.471 (08/97) 5 Table 2M.471- Level 2 notification service elements (Level 2) Element of service orig. Rec. Message identification Originator indication (to provide “notification Message recipient (to provide the “original intende
35、d originator identification“) message recipient indication“) B B B B B B EOS i# F.472 and FA00 Annex A/B reference Original encoded information types indication Class of message delivery Notification details (to provide): - responsibiiity acceptance or non-acceptance indication; - date and time; - f
36、ailure reason and diagnostic information; - message durationa); - delivery durationa); - receiving terminai identificationa); - time last attempteda); - number of attemptsa); - delivered message duration ). B.41 B.55 B A B A E B A.5JF.472 A.33 A.UF.472 A.7F.472 Where a message contains a multiple re
37、cipient address, it shall be possible for the transit facility to accept responsibility for some recipient addresses and to onward transfer to one or more Voice SFUs or transfer systems the responsibility for other recipient addresses. The transfer of messages between VM S - organization; - organiza
38、tional unit(s); - physical address lines; - voice-mail network address. Message information O 1 intended duration, minutes I O I class of service - delivery schedule I O I class of service - precedence service level I O Originator addressing information includes: - address (box number); - organizati
39、on; - organizational unit(s); - physical address lines; - voice-mail network address. O Additional recipients Note 2 O D NOTE 1 - Provision of voice signature is by bilateral agreement. NOTE 2 - Display of additional recipients is an item for further study. Provided by originating Voice SFU. Provide
40、d by destination Voice SFU. 8.6 Successfuiunsuccessful message transfer notifications A Level 1 includes information indicating the destination Voice SFUs successful and/or unsuccessful acceptance of responsibility for the message on a per recipient basis. A Level 1 which only contains information r
41、egarding unsuccessful transfer shall be generated by either the destination Voice SFTJ or the transit facility as soon as it is determined that responsibility for the message on a per recipient basis cannot be accepted or transferred. A Levei 1 for successful transfer shall only be returned when req
42、uested. The request shall be processed on a per recipient basis. An unsuccessful message transfer is indicated by the gederation of a negative Level 1 (there is no requirement for the generation of a negative Level 2 in this case). It shall be essential to return a Level 1 for unsuccessful transfer
43、on a per recipient basis. 8.7 Successful/unsuccessful message delivery notifications A positive Level 2 may indicate successful message delivery. It shall be returned to the originating Voice SF on a per recipient basis. A Level 2 for successful message delivery shall only be returned when requested
44、 (Le. precedence service level indicates “certified“). The request shall be processed on a per recipient basis. 8 Recommendation F.471 (08/97) STD.ITU-T RECMN F.471-ENGL 1777 LiBb2591 b38917 601 m A negative Level 2 may indicate unsuccessful message delivery. It shall be returned to the originating
45、Voice SF on a per recipient basis. Level 2 notifications shall be generated for any unsuccessful delivery. In the context of this service, message delivery occurs when the VMS accepts responsibility for the message. 8.8 Voice coding encoding conversion If a Voice SF supports voice coding encoding ot
46、her than the default format defined in 7.3 (see Recommenda- tion G.726), then the Voice SFU must support conversion between the default encoding and the other supported voice coding formats. Transfer of the message in other encoding is by bilateral agreement only. 9 Quality of service The quality of
47、 the subject voice encoded messages received from the originating VM S&F service should not be adversely affected by any intermediary or delivering Voice SF, transfer service, or intermediary VM S&F service through which the message may pass. The quality of the voice message as received from the ori
48、ginating voice-mail system should not be adversely affected by any Voice SFU, transit facility, or any transmission service between Voice SFus through which the voice-mail message may pass. 9.1 Objectives The following quality of service objectives are defined for messages passed across the internat
49、ional boundary for delivery by a destination Voice SF. The overall service delivery objectives are specified in Table 2. In order that the destination Voice SF is able to meet the objectives as stated in Table 2, the originating Voice SFU should transfer the message according to the objectives illustrated in Figure 3 and described in Table 5. The objectives for time, TA, TB, TI, T2 and “3 should be met for at least 95% of messages (during any one-hour period) 95% of the time. The number of attempts to deliver a message to the destination termina
