1、 - CCITT RECMN*Q.1221 93 4862591 0580895 734 W INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.1211 (03/93) GENERAL RECOMMENDATIONS ON TELEPHONE SWITCHING AND SIGNALLING INTELLIGENT NETWORK INTRODUCTION TO INTELLIGENT NETWORK CAPABILITY SET 1 ITU-T Reco
2、mmendation Q.1211 (Previously “CCIlT Recommendation”) CCITT RECNN*Q-J2JL 93 E 4862593 0580896 670 FOREWORD The IT Telecommunication Standardization Sector (IT-T) is a permanent organ of the International Telecom- munication Union. The IT-T is responsible for studying technical, operating and tariff
3、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 the topics for study by the ITU-T Study Groups which, in their turn, produce Re
4、commendations on these topics. ITU-T Recommendation Q.1211 was prepared by the IT-T Study Group Xi (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 (IT), the CCITT ceased to exist as o
5、f 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (IT-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 Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector.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
6、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 proper terminology related to the new ITU structure. 2 telecommunication administrati
7、on and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O IT 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopy
8、ing and microfilm, without permission in writing from the ITU. - CCITT RECMN*Q.LZLL 93 48b259L 0580897 507 W CONTENTS SUMMARY . 1 7 3 4 5 5.1 6 7 Introuction . Phased standardization General description and scope of CS-1 . 3.1 Criteria for CS-1 . 3.2 Evolution of CS-1 . Overviehi of CS-1 Recomrnenck
9、Niions . Service aspects . Type A and Type B services . 5.2 Target .sets of CS-I services and service features . 5.3 Network aspects . 6.1 Network functions . 6.3 Feature interactions . 6.4 Consistency among CS-1 supported service features Functional relationships and interfaces 7.1 Reference points
10、 and identifiers for functional relationships 7.2 Control classes 7.3 7.4 CS-1 non-IN connection and call control 7.5 CS-1 IN service conUol . 7.6 Service management for CS-1 . 7.7 Network interworking in CS-1 7.8 Summary of CS-1 control relationships . Network support of CS-1 services 6.2 Control a
11、rchitecture principles Reference point identifiers and control relationships . Annex A . Examples of relationships .and mappings between CS-1 services and service features Annex B . Short prose descriptions of targeted services and service features B.1 B.2 Descriptions of targeted services . Descrip
12、tions of targeted service features Recommendation Q.1211 (03/93) Page 11 1 1 1 1 2 3 3 3 4 4 5 5 7 9 9 10 10 10 10 11 12 12 13 15 16 18 18 26 i SUMMARY Intelligent network capability set 1 is the first standardized stage of the intelligent network (IN) as an architectural concept for the creation an
13、d provision of telecommunications services. This Recommendation gives an introduction to capability set 1 (CS-1) by providing an overview and definition of CS-1 and by describing its main characteristics and overall capabilities. It defines the service aspects, network aspects and functional relatio
14、nships that form the basis of the CS- 1 capabilities. This Recommendation is the first in the Q.121-Series Recommendations devoted to CS-1. It builds on the architecturai principles of IN as described in the Q. 120x-Series Recommendations. The CS-1 Recommendations (Q.121-Series) form a useful basis
15、for achieving implementation experience. As with any project of this size and complexity, it can be anticipated that there may be some difficulties in intenvorking the various implementations of IN CS-1 physical elements. In order that the IN objective for working in a multi-vendor environment may b
16、e fully achieved, the IN CS-1 Recommendations text may go through some future revision in the light of implementation experience. ii Recommendation Q.1211 (03/93) Recommendation Q.1211 INTRODUCTION TO INTELLIGENT NETWORK CAPABILITY SET 1 (Helsinki, 1993) 1 Introduction Intelligent network capability
17、 set 1 is the frrst standardized stage of the intelligent network (IN) as an architectural concept for the creation and provision of telecommunications services. This Recommendation gives an introduction to capability set 1 (CS-1) by providing an overview and definition of CS-1 and by describing its
18、 main characteristics and overall capabilities. 2 Phased standardization The intelligent network (IN) is an architectural concept for creation and provisioning of new services which is characterized by: a) extensive use of information processing techniques; b) efficient use of network resources; c)
19、modularization and reusability of network functions; d) integrated service creation and implementation by means of modularized, reusable network functions; e) flexible allocation of network functions to physical entities; f) portability of network functions among physical entities; g) standardized c
20、ommunications between network functions via service independent interfaces; h) service subscribers control of some subscriber-specific service attributes; i) service user control of some user-specific attributes; j) standardized management of service logic. The implementation of the IN architecture
21、will facilitate the rapid introduction of new services. Its architecture can be applied to various types of telecommunications networks, which inclue: public switched telecommunications network (PSTN). public switched packet data network (PSPDN), mobile, and integrated services digital networks (N-
22、and B-ISDN). The ultimate IN is an evolving target, therefore in order to take full advantage of the technological possibilities at a c given point in time it is necessaty to define specific phases in the evolution to a target architecture. This phased approach is shown in Figure 1. This Recommendat
23、ion provides the description of CS-1 at time Ti as represented in Figure 1. 3 General description and scope of CS-1 3.1 Criteria for CS-1 CS-1 defines an initial subset of IN Capabilities that meet the following general criteria: a) b) CS-1 is a subset of the target intelligent network architecture;
24、 CS-1 is a set of defuitions of capabilities that is of direct use to both manufacturers and network operators; Recommendation Q.1211 (03/93) 1 CCITT RECMN*Q.L23L 93 Bi 4862593 0580900 921 W Capabilities sels Time I I I b Ti T2 TX T1137310-9i/dOl Areas: 0 IN concept and modelling Definitim of next C
25、C Recommendation for CS-X FIGURE UQ.1211 Sequencing of capability sets c) CS-1 provides network capabilities to support services either defined or in the process of being defined by CCITT (e.g . universal personal telecommunications service, freephone, and virtual private network services such as pr
26、ivate numbering plan). CS-1 also provides capabilities to support the introduction of services which may neither be standardized by CCIIT, nor be part of the proposed set of targeted services: ) CS-1 is the first standardized stage of evolution based upon the existing technology base and on evolvabi
27、lity requirements addressed in 3.2. The CS-1 architecture may be supported over PSTN, ISDN, and mobile networks. 3.2 Evolution of CS-1 The CS- 1 Recommendations (Q. 12lx-Series) form a useful basis for achieving implementation experience. As with any project of this size and complexity, it can be an
28、ticipated that there may be some difficulties in interworking the various implementations of IN CS-1 physical elements. In order that the IN objective for working in a multi-vendor environment may be fully achieved, the IN CS-1 Recommendations text may go through some future revision in die light of
29、 implementation experience. The CS-1 architecture takes into account the evolution requirement, i.e., it supports the CS-1 targeted services but its fiinctionalities are designed to evolve towards the future capability sets (CS-2 and beyond). Therefore, the CS-1 capabilities are defined without any
30、assumptions that are known to limit their ability to evolve into future capability sets. 2 Recommendation Q.1211 (03/93) _ CCITT RECMN*Q.3233 93 E 48b2593 0580903 8b8 4 Overview of CS-1 Recommendations Table 1 contins u11 overview of the Recommendations that are specifically related to CS-1: TABLE U
31、Q.1211 CS-1 Recommendations Reaimmendation Title I Q.1211 y.1213 4.1214 Q.1315 Q.121X Q.1219 Introduction tu intelligent network capability set 1 Glohal functional plane for intelligent network CS-1 Ilistributed functional plane for intelligent network CS-1 Physical plane for intelligent network CS-
32、1 Intelligent network interface specifications for capability set 1 Intelligent network users guide for capability set 1 5 Service aspects Although, by nature, the IN is 8 service independent architecture, it is relevant to describe the general CS-1 service cnpabilities. The services and service fea
33、tures that are to be supported by CS-1 are fundamental to the CS-1 service independent building blocks (SIBS), call processing model and service control principles. 5.1 Type A and Type B services CS-1 capabilities are intended to support services and service features that fall into the Gitegory of s
34、ingle ended”, “single point of control” services referred to as Type A, while all other services are placed in a category called Type B. The following definitions apply: A single-ended service feature ,applies to one and only one party in a call and is orthogonal (independent) at both the service an
35、d tcplogy levels to any other parties that may be participating in the call. orthogoiiality allows another instance of the same ur a different single-ended service feature to apply to another party in the srne call as long as the service feature instances do not have feature interaction problems wit
36、h each other. Single point of control describes a control relationship where the sune aspects of a cdl are influenced by one and only cine service control function at .any point in time (see also 6.2.1). CS-1 standards do not encompass “Type B” services for the following reasons: a) )periticmd compl
37、exity In Type B services, several IN subscribers may be associated within a single call. During the call, subsaibers may be added or dropped. These associations take place physically in the switches involved in the call (SSF/CCF functions) under the control of an SCF. The SCF will need rules to hand
38、le feature arbitration between subscribers involved in the call (e.g. incompatible screening lists). This may have to involve real-time consultations between the SCFs that “represent” the various parties involved in the call. Rules will Aso be required to handle topological decisions (e.g. which phy
39、sical switches should be chosen to “join” groups of subscribers scattered around a network?). Recommendation Q.1211 (03/93) 3 CCITT RECMNPQ-3233 93 W 4062593 0500902 7T4 M b) Itiiplementation complexity Type B services may involve manipulation of switch connection resources by service logic located
40、in an SCF. This means that an ?abstracted? view of the switch?s connection resources must be made available to external service logic. Models have been formulated to accommodate appropriate ?abstracted? views, but to date these are theoretical proposals. A very large investment in switch software re
41、design may k required to realize such models. In contrast, the switch software modifications to accommodate Type A services are relatively modest in scope and are well understood. c) Control complexity Type A services are characterized by a relatively simple control relationship between SSF and SCF.
42、 The SSF is a ?client? for service-related information provided by the SCF, however, the switch retains connection control at all times. In contrast, the control relationship between SCF and SSF in Type B services may require the sharing of connection control between the switch and external service
43、logic. The information flows need to be rich in parameters to manage what is essentially a peer-peer, distributed processing relationship. As there are considerable differences in operational, implementation, and control complexity between Type A and Type B services, CS-1 is targeted to support Type
44、 A services only. There are some circumstances in which it will be possible to apply ?Typ, A? IN technology to certain aspects of ?Type B? services. This applies to switch-based services in general, whether these services be of ?Type A? or ?Type B?, and to ?Type B? services in general, whether these
45、 be switch-based or CS-x based. Further detail can be obtained from Recommendation Q.1214. 5.2 Target sets of CS-1 services and service features Tables 2 and 3 contain the target sets of CS-1 services and service features. The target sets can be used to identi and verify the service-independent capa
46、bilities of CS-1. Examples of relationships and mappings between these CS-1 services and service features are shown in Annex A. Annex B provides short prose descriptions of targeted services and service features. These were used to develop the current Q. 12lx-Series Recommendations as CS-1 is intend
47、ed to support evolutionary new services. The descriptions provided for the targeted services and service features are for the above-mentioned purposes only and are not to be used by service designers for service creation. Definitions of ?service? and ?service feature?: A service is a stand-alone com
48、mercial offering, characterized by one or more core service features, and can be optionally enhanced by other service features. A service feature is a specific aspect of a service that can also be used in conjunction with other serviceshervice features as part of a commercial offering. It is either
49、a core part of a service or an optional part offered as an enhancement to a service. 5.3 Network support of CS-1 services The services are to be supported over various networks. For IN CS-1 applications the following networks are considered: i) PSTN ii) ISDN (Public and private networks); iii) PLMN. 4 Recommendation Q.1211 (03/93) CCITT RECMN*Q*1211 93 Y862591 0580703 630 TABLE 2/Q.1211 Target set of CS-1 services Abbreviated dialling Account card calling Automatic alternative hilling Call distribution Call forwarding Call rerouting
