1、National Standard of CanadaCAN/CSA-ISO/IEC 15055-01(ISO/IEC 15055:1997)International Standard ISO/IEC 15055:1997 (first edition, 1997-05-15), has been adopted withoutmodification as CSA Standard CAN/CSA-ISO/IEC 15055-01, which has been approved as a National Standardof Canada by the Standards Counci
2、l of Canada.ISBN 1-55324-345-5 March 2001G35G48G49G48G55G48G51G46G48 G51G58G50G45G48G55G2cG36G32G12G2cG28G26 G14G18G13G18G18G1d G14G1cG1cG1aGbG28GcThe Canadian Standards Association, which The Standards Council of Canada is theoperates under the name CSA International coordinating body of the Nation
3、al Standards(CSA), under whose auspices this National Standard system, has been produced, was chartered in 1919 and a federation of independent, autonomousaccredited by the Standards Council of Canada to the organizations working towards the furtherNational Standards system in 1973. It is a not-for-
4、profit, development and improvement of voluntarynonstatutory, voluntary membership association standardization in the national interest.engaged in standards development and certification The principal objects of the Council are to foster activities. and promote voluntary standardization as a means C
5、SA standards reflect a national consensus of of advancing the national economy, benefitingproducers and users including manufacturers, the health, safety, and welfare of the public,consumers, retailers, unions and professional assisting organizations, and governmental agencies. The and protecting th
6、e consumer, facilitating domestic standards are used widely by industry and commerce and international trade, and furtheringand often adopted by municipal, provincial, and federal international cooperation in the field of standards.governments in their regulations, particularly in the A National Sta
7、ndard of Canada is a standardfields of health, safety, building and construction, and which has been approved by the Standardsthe environment. Council of Canada and one which reflects aIndividuals, companies, and associations across reasonable agreement among the views of aCanada indicate their supp
8、ort for CSAs standards number of capable individuals whose collectivedevelopment by volunteering their time and skills to interests provide to the greatest practicable extentCSA Committee work and supporting the Associations a balance of representation of producers, users,objectives through sustaini
9、ng memberships. The more consumers, and others with relevant interests, asthan 7000 committee volunteers and the 2000 may be appropriate to the subject in hand. Itsustaining memberships together form CSAs total normally is a standard which is capable of makingmembership from which its Directors are
10、chosen. a significant and timely contribution to theSustaining memberships represent a major source of national interest.income for CSAs standards development activities. Approval of a standard as a National Standard ofThe Association offers certification and testing services Canada indicates that a
11、 standard conforms to thein support of and as an extension to its standards criteria and procedures established by thedevelopment activities. To ensure the integrity of its Standards Council of Canada. Approval does notcertification process, the Association regularly and refer to the technical conte
12、nt of the standard; thiscontinually audits and inspects products that bear the remains the continuing responsibility of theCSA Mark. accredited standards-development organization.In addition to its head office and laboratory complex Those who have a need to apply standards arein Toronto, CSA has reg
13、ional branch offices in major encouraged to use National Standards of Canadacentres across Canada and inspection and testing whenever practicable. These standards are subject agencies in eight countries. Since 1919, the Association to periodic review; therefore, users are cautioned has developed the
14、 necessary expertise to meet its to obtain the latest edition from the organizationcorporate mission: CSA is an independent service preparing the standard.organization whose mission is to provide an open and The responsibility for approving Nationaleffective forum for activities facilitating the exc
15、hange of Standards goods and services through the use of standards, of Canada rests with thecertification and related services to meet national and Standards Council of Canadainternational needs. 270 Albert Street, Suite 200For further information on CSA services, write to Ottawa, Ontario, K1P 6N7CS
16、A International Canada178 Rexdale BoulevardToronto, Ontario, M9W 1R3CanadaAlthough the intended primary application of this Standard is stated in its Scope, it is importantto note that it remains the responsibility of the users to judge its suitability for their particular purpose.Registered trade-m
17、ark of Canadian Standards AssociationInformation technology Telecommunications and information exchange betweensystems Private Integrated Services Network (PISN) Specification, FunctionalCAN/CSA-ISO/IEC 15055-01 Model and Information Flows Message Waiting Indication Supplementary ServiceMarch 2001 C
18、SA/1CAN/CSA-ISO/IEC 15055-01Information technology Telecommunications andinformation exchange betweensystems Private IntegratedServices Network (PISN) Specification, Functional Model andInformation Flows MessageWaiting Indication SupplementaryServiceCSA PrefaceStandards development within the Inform
19、ation Technology sector is harmonized with internationalstandards development. Through the CSA Technical Committee on Information Technology (TCIT),Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Committee 1 onInformation Technology (ISO/IEC JTC1) for the Standard
20、s Council of Canada (SCC), the ISO memberbody for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of theInternational Telecommunication Union (ITU), Canada participates in the International Telegraph andTelephone Consultative Committee (ITU-T).This International S
21、tandard was reviewed by the CSA TCIT under the jurisdiction of the StrategicSteering Committee on Information Technology and deemed acceptable for use in Canada. (A committeemembership list is available on request from the CSA Project Manager.) From time to time, ISO/IEC maypublish addenda, corrigen
22、da, etc. The CSA TCIT will review these documents for approval and publication. For a listing, refer to the CSA Information Products catalogue or CSA Info Update or contact a CSA Salesrepresentative. This Standard has been formally approved, without modification, by these Committeesand has been appr
23、oved as a National Standard of Canada by the Standards Council of Canada.March 2001 CSA International 2001All rights reserved. No part of this publication may be reproduced in any form whatsoever without the priorpermission of the publisher. ISO/IEC material is reprinted with permission. Inquiries r
24、egarding this NationalStandard of Canada should be addressed to CSA International, 178 Rexdale Boulevard, Toronto, Ontario,M9W 1R3.INTERNATIONAL TANDARD First edition 1997-05-l 5 Information technology - Telecommunications and information exchange between systems - Private Integrated Services Networ
25、k - Specification, functional model and information flows - Transit counter additional network feature Technologies de Iinforma tion - TMcommunications et khange dinforma tion entre systgmes - R otherwise it requests rejection of the call request. Final FE2 The final FE2 terminates ANF-TC. 7.1.3 Rel
26、ationship of functional model to basic call functional model FE1 shall be collocated with the Originating CC, an Incoming Gateway CC, or a Transit CC. An intermediate FE2 shall be collocated with a Transit CC. The final FE2 shall be collocated with the Terminating CC or an Outgoing Gateway CC. Figur
27、e 3 shows an example of the relationship with the basic call functional model. ra interm. 0 ra ra FE2 , Origin. r2 A Transit *L r2 Transit b r2 I Termin CC CC cc cc . Figure 3 - Example relationship between models for ANF-TC and basic call 7.2 Information flows 7.2.1 Definition of information flows
28、7.2.1.1 ra-TC ra-TC is an unconfirmed information flow across ra from FE1 to FE2 and between FE2s. Table 1 lists the service elements within the ra-TC information flow. M in the column headed “Request” indicates that the service element is mandatory. Table 1 - Content of ra-TC Service element Allowe
29、d Value Request r Transits count Integer (Note) M I Note: The allowed range is (0, , max) where max is a network dependent maximum value. Service element Transits count shall always be included in the ra-TC request/indication information flow and contain the current value of the transit counter. 7.2
30、.2 Relationship of information flows to basic call information flows ra-TC shall be sent in conjunction with an r2-Setup request/indication flow. 7.2.3 Examples of information flow sequences A stage 3 standard for ANF-TC shall provide signalling procedures in support of the information flow sequence
31、s specified below. In addition, signalling procedures should be provided to cover other sequences arising from error situations, interactions with other supplementary services, different topologies, etc. 6 OISO/IEC ISO/IEC 15055:1997 (E) In the figures, ANF-TC information flows are represented by so
32、lid arrows and basic call information flows are represented by broken arrows. An ellipse embracing two information flows indicates that the two information flows occur simultaneously. Within a column representing an ANF-TC functional entity, the numbers refer to functional entity actions listed in 7
33、.3. The following abbreviations are used: req request ind indication 7.2.3.1 Normal operation of ANF-TC Figure 4 shows the information flow sequence for normal operation of ANF-TC. 101 A ra-TC reqlind I m 201, A ra-TC req/ind r2-SETUP req/ind )202 - r2-SETUP req/ind ” L-w- -7-l Figure 4 - Informatio
34、n flow sequence - normal operation of ANF-TC 7.2.3.2 Transit counter limit exceeded Figure 5 shows the information flow sequence for the case that the allowed limit of the transit counter is exceeded. ra r3 req/ind -_- Figure 5 - Information flow sequence - transit counter limit exceeded 7.3 Functio
35、nal entity actions The following FE actions shall occur at the points indicated in the figures of 7.2. 7.3.1 Functional entity actions of FE1 101 Recognize the invocation of ANF-TC, set the transit counter to the initial value and send ra-TC request/indication to FE2. 7.3.2 Functional entity actions
36、 of FE2 201 Acting as an intermediate FE2, on receiving ra-TC request/indication with a transit counter value below the limit, increment the value and send ra-TC request/indication to the next FE2. 202 Acting as the final FE2, on receiving ra-TC request/indication, terminate ANF-TC. 203 Acting as an
37、 intermediate FE2, on receiving ra-TC request/indication with a transit counter value equal to or higher than the allowed limit, reject the call setup request. 7 ISO/IEC 15055: 1997 (E) OISO/IEC 7.4 Functional entity behaviour The FE behaviours shown below are intended to illustrate typical FE behav
38、iour in terms of information flows sent and received. The behaviour of each FE is shown using the Specification and Description Language (SDL) defined in CCITT Rec. 2.100 (1988). 7.4.1 Behaviour of FE1 Figure 6 shows the normal behaviour of FE1 . Input symbols from the left represent internal stimul
39、i. Output symbols to the right represent information flows to FE2. initialize transit counter ra-TC request Figure 6 - ANF-TC, SDL for functional entity FE1 OISO/IEC ISO/IEC 15055:1997(E) 7.4.2 Behaviour of FE2 Figure 7 shows the normal behaviour of FE2. Input symbols from the left represent informa
40、tion flows from other FE%. Output symbols to the right represent information flows to another FE2. Output symbols to the left represent internal stimuli. increment transit counter ra-TC request Figure 7 - ANF-TC, SDL for functional entity FE2 ISO/IEC 15055:1997 (E) OISO/IEC 7.5 Allocation of functio
41、nal entities to physical equipment Table 2 shows the allocation of functional entities to physical equipment. Table 2 - Scenarios for the allocation of FEs to physical equipment Scenario 1 Scenario 2 FE1 Originating PINX Transit PINX FE2 (intermediate) Transit PINX Transit PINX FE2 (final) Terminati
42、ng PINX Terminating PINX 7.6 Interworking considerations ANF-TC applies only to portions of a call that lie within the PISN. For calls to and from other networks the functional entities are allocated to physical equipment as shown in table 3. Table 3 - Scenarios for the allocation of FEs to physical
43、 equipment in interworking situations I I FE1 I FE2 (intermediate) I FE2 (final) I , Scenario 3 Originating PINX Transit PINX Outgoing Gateway PINX Scenario 4 Transit PINX Transit PINX 7 Outgoing Gateway PINX I Sceiaiio 5 Incoming Gateway PINX Transit PINX Terminating PINX 1 Scenario 6 Incoming Gate
44、way PINX Transit PINX I Outgoing Gateway PINX 10 This page intentionally left blank This page intentionally left blank This page intentionally left blank ISOAEC 15055: 1997(E) ISOAEC ICS 35.110 Descriptors: data processing, information interchange, tekcommunications, network interconnection, telecom
45、munication network, private network, BSDN, data transmission, services. Price based on IO pages A not-for-profit private sector organization Organisme sans but lucratif du secteur prive178 Rexdale Boulevard 178, boulevard RexdaleToronto, Ontario, Canada M9W 1R31 800 463.6727+ 1 416 747.4044www.csa-international.orgISBN 1-55324-345-5
