1、CEPT T/CAC*S*LO-L E 92 2326434 0031485 328 CEPT Telecom O T/CAC S 10.1 E Page 1 Recommendation TICAC S 10.1 E (Cannes 1983, revised in Odense 1986, Vienna 1989 (CAC) and Athens 1992) Formerly Recommendation T/SF 31 -01 E GENERAL ASPECTS OF AN INTEGRATED SERVICES DIGITAL NETWORK (ISDN) Recommendation
2、 proposed by Working Group T/GT 7 “Services and Facilities (SF) Amendments proposed by Project Team Service Descriptions for the ISDN (SDI) Text of the Recommendation adopted by Commercial Action Committee (CAC) O CONTENTS O. FOREWORD 1. GENERAL 2. TYPES OF ISDN SERVICES 3. USER INTERFACES (EXCLUDIN
3、G ISPBXs) 4. CALL HANDLING PROCEDURES 5. CHANNEL ALLOCATION 6. NUMBERING ADDRESSING AND SERVICE INDICATION ASPECTS 7. DEFINITION OF BUSY IN AN ISDN O Figure 1 (T/CAC S 10.1 E): Bearer Service Attributes Figure 2 (T/CAC S 10.1 E): Differences between Bearer Services and teleservices Figure 3 (T/CAC S
4、 10.1 E): inter-relationship of Services Figure 4 (T/CAC S 10.1 E): Procedural Aspects of Call Offering Edition of November 20, 1992 CEPT T/CAC*S*SO.S E 92 23ZbULU OOLLYb 2611 m WCAC S 10.1 E Page 2 CEPT Telecom O. FOREWORD An ISDN is a network providing end-to-end digital connectivity to support a
5、wide range of telecommunication services. These services include voice and non-voice services to which customers have access by a small set of standard user-network interfaces. In the I-Series CCITT has prepared Recommendations which provide principles and guidelines on the ISDN concept as well as d
6、etailed specifications. Based on these principles the European Commission has embarked on an European ISDN. In 1989 a Memorandum of Understanding (MOU) on ISDN was agreed and signed by European network operators to enable European ISDN services to be offered across Europe in 1992. This includes a ma
7、ndatory minimum set of services which all signatories will provide. This MOU requires: - standards for a common range of services which all signatories will follow: - standards for user-network interfaces and protocols having the objective of enabling any customer equipment implemented to the requir
8、ed standards to be connected to and operated with the ISDN provided by each party (teminal interchangeability); - standards for interconnecting national systems in order to provide international services. ETSI - The European Telecommunications Standards Institute (ETSI) has published or will publish
9、 both European Telecommunications Standards (ETSs) or ETSI Technical Reports (ETRs) to specify or provide guidance on the services and standards for the European ISDN, thereby also taking into account the requirements of private networks (private ISDNs) which support identical or similar services to
10、 those of the public ISDN. CEPT The SF ISDN Recommendation, in general, is based on CCIlT Recommendations, but as a target it should give guidance in the area of services descriptions as an European version of the CCIlT Recommendation (without non-European options and with European priorities of ser
11、vices). - In the new edition of the SF ISDN Recommendation the additional target is to give guidance in the areas of service descriptions (operational requirements, etc.) to the relevant ETSI standardisation bodies (ETSI TCs, etc.) beyond the MOU ISDN services and priorities. 1. GENERAL 1.1. Service
12、s Design That, in general, the design of services and the location of their features must aim to meet the service requirements in full, including maintenance, recognise the varying degrees of usage, and provide the service and supplementary service. Ediiion o November 20, 1992 CEPT T/CAC*S*lOgl E 92
13、 2326434 0011487 1TO W CEPT Telecom TKAC S 10.1 E Page 3 1.2. 1.3. 1.4. Evolution of ISDN That the ISDN should be able to respond to new requirements quickly and at reasonable cost. The design should provide flexibility to meet foreseen requirements and take advantage of improved technology. That th
14、e transition from an existing network to a comprehensive ISDN may require a period of time. During this period arrangements must be developed for the interworking of services on ISDNs and services on other networks. That the evolution of the ISDN services should take into account the Intelligent Net
15、work (IN). Commercial Benefits of the ISDN That network operators may utilise the technical facilities of the ISDN to provide customers with one or more of a range of services via a common access point at their premises. This access point enables the user to use more than one service simultaneously.
16、 That the range includes Bearer Services (T/CAC S 10.2), Teleservices (T/CAC S 10.3), and Supplementary Services (T/CAC S 10.5, 10.6 and 10.7). That the ISDN is seen as a powerful service provision tool for network operators whose main commercial benefits appear to be: - the ease and speed with whic
17、h the composition of a given customers package of Bearer Services can be attered from time to time to take account of changing needs; - the ease and speed with which new types of Bearer Services can be offered to a customer once that customer is served by the ISDN; - the expected improvement in qual
18、ity of service on calls connected via the ISDN; - the eventual attraction when ISDN penetration and availability is more general of being a subscriber to a service used by correspondents. That the customer services that may be offered in the form of Bearer Services available at the network (T) inter
19、face fall into the following groups: - Leased point-to-point permanent circuits (accessed via 64 kbit/s, 384, or 1920 kbWs); - Access via 64 kbits, 384 kbit/s, or 1920 kbWs to one or mre of a number of switched services; - Access via 64 kbWs and 16 kbits to packet mode services; - Access via broadba
20、nd capabilities. That the customer services that may be offered in the form of Teleservices from a common ISDN access fall into two groups: - Leased Point-to-Point Permanent Circuits; - Teleservices, however, include the terminal apparatus at the customers premises and this apparatus may itself intr
21、oduce a number of further variants in the presentation of the service to the customer. Access to one or more of a number switched services. Security That for administrative securtty reasons, certain sensitive functions (e.g. charging, program- ming, traffic management) shall be located only inside p
22、remises or equipment that is physically secure from interference by persons other than authorised staff. This applies also from the remote access to a user network management service (e.g. performance monitoring and accounting management). Edition of November 20. 1992 CEPT T/CAC*S*SOaS E li! M 232b4
23、54 005L488 037 M WCAC S 10.1 E CEPT Telecom Page 4 1.5. 1.6. 1.7. 1.8. 1.9. 1.9.1 * 1.9.2. 1.9.3. 1.10. Charging That the network operator shall have the ability to charge at the outset during and at the end of a call. Charging requirements may mainly be in accordance with the work done by the netwo
24、rk when providing the service. This needs flexibility and typically requires: (a) processing cost (b) switching cost (c) transmission cost (d) signalling cost as possible components of charging. Note: The charging chouid include wage charges, which may indude a call setup charge, a call duration cha
25、rge, and facilities usage charges and may vary depending of time or day. Testing That the network should be able to prove remotely whether or not the network termination is in working order. It is also desirable to be able to remotely prove whether or not the users terminal equipment is in working o
26、rder. Power Failure That under conditions of local power failure at least one terminal on the basic access should be operational for basic telephony service. In addition, alarm (warning) transmission should also be possible under these conditions. Provision, Removal and Withdrawal of Service That th
27、e provision and removal of a service and the temporary withdrawal of a SOrviCe under any conditions is covered by the individual service. Physical Connectlon For Basic Access Terminals That the uitimate aim should be the standardisation of a universal socket allowing the connection of any type of te
28、rminal with the appropriate interface to the ISDN basic access. For Primary Rate Access Installations That the uitimate aim should be the standardisation of a universal socket installation allowing the connection of the appropriate interface to ISDN primary rate access. For ISPBX Terminals That the
29、uitimate aim for connection of terminals to ISPBXs should be the adoption of the socket defined for basic access terminals. Terminal Interchangeability That the terminals connected to the ISDN basic access and behind the ISPBX should be Edition of November 20, 1992 CEPT T/CAC*S*LO.L E 92 2326434 003
30、3489 T73 9 CEPT Telecom 2. 2.1. 2.2. 2.3. 2.4. 2.5. T/CAC S 10.1 E Page 5 compatible. Note: The principie of terminal interchangeability is to ensure that a terminal shall be (as far as possible) capable of participating in services independent of the actual network to which it is attached, .e. diff
31、erent national ISDNs, private ISDNs, etc. TYPES OF ISDN SERVICES Service Types Telecommunication services are divided into two broad families, .e.: - Bearer services, and - Teleservices. That a supplementary service modifies or supplements a basic telecommunication service. Consequently, it cannot b
32、e offered to a customer as a stand-alone service. It must be offered together with or in association with a basic telecommunication service. The same supplementary service may be common to a number of telecommunication services. That the ISDN has to provide a minimum set of Bearer Services, Teleserv
33、ices, and Supplementary Services (see Fig. 3). Bearer Services That a set of internationally standardised bearer services should be offered by network operators. A list of bearer services is given in Recommendation T/CAC S 10.2. See also CCITT Recommendation 1.230. Note 1 : Note 2: The multiplexing
34、of multiple subrate information streams made by users are on their own responsibility. The circuitmode bearer services are typically charactensed by provision of user information over one type of channel and signalling over another type of channel. The packetmode bearer services involve packet handl
35、ing functions. Description of Bearer Services Bearer services are fully described by prose definitions and descriptions which all together define the service characteristics as they apply at a given reference point where the customer accesses the service. CCIT Recommendation 1.140 and 1.210, Annex B
36、, describe the use of attributes for this purpose. Teleservices That a set of international standardised teleservices should be offered by network operators. A list of standardised teleservices is given in Recommendation T/CAC S 10.3. See also CCITT Recommendation 1.240. Description of Teleservices
37、Teleservices provides the full capacity for communication by means of terminal and network functions. CCIlT Recommendation 1.21 O, Annex C, describes the use of attributes for this purpose. Edition of November 20. 1992 WCAC S 10.1 E Page 6 CEPT Telecom 2.6. 2.7. 2.8. 3. 3.1. 3.2. 3.3. Supplementary
38、Sewices That an agreed list and agreed definitions of supplementary services, the relevance of supplementary services to bearer and tefeservices, and the agreed operational require- ments of ISDN supplementary services are given in Recommendation T/CAC S 10.5,10.6, and 10.7. Commonality between Publ
39、ic and Private ISDN Services As a basic objective the standardised ISDN services should be designed to cover both public and private ISDN requirements. Introduction of New Sewices That the introduction of new services should not prejudice telephony or cause any significant penalties to be incurred b
40、y the major services in the network. USER INTERFACES (EXCLUDING ISPBB) Bask Access Capabllitles That for the basic access the capability of carrying at least 2 simuitaneous calls should be provided. These may use one or more channels provided exclusively for the transfer of user information and a ch
41、annel whose primary use is for user-to-network signalling. That the both-way signalling system beiween the users premises and the network shall be adequate to support existing services and also provide the capability of introducing new services on the basic access without adversely affecting the exi
42、sting or new services. That the user should be given the possibility to ascertain the state of his access channels, for instance whether a channel is busy or whether a channel is allocated to a particUlar service. This may be provided automatically. That the user should be able to employ his access
43、to the neiwork for the operation of one or more terminals of either the same or different types either sequentially or simuitane- ously, using the same links between his premises and the local switching node. The number may be restricted by the number of parts on the network termination. Connection
44、of More than One Terminal That it should be possible to connect any mixture of terminais up to a maximum of eight terminals to the same basic access. Electrical and Protocol Characteristics 3.3.1. Basic Rate Access That one interface (the S/T interface) exhibiting standardised electrical and protoco
45、l characteristics shall be adopted for the ISDN basic rate access (2 B + D). Note 1: it is recognised that network operators may wich to offer other standardiced interfaces via terminal adapters, e.g. X.21, X.25, V se That the general rules should be: 1) the operation of the rules should not restric
46、t unduly the quantity of traffic that a user can offer to the network: 2) the operation of rules should not allow the completion of incoming calls to be unduly obstructed. That users should be able to choose options within the channel allocation rules, e.g. to take account of time periods or variati
47、ons of terminal equipment. That the network operators should be able to gain access to a record of all changes to channel allocation for network operation and maintenance. However, whilst the mechanism that controls channel allocation should be owned and controlled by the Network Operator. NUMBERING
48、, ADDRESSING, AND SERVICE INDICATION ASPECTS Numbering spects That each network termination should be selected by one subscriber number both in cases of ISDN basic access and also for primary rate ISDN access. O O Edition of November 20, 1992 CEPT T/CAC*S*LO*L E 72 W 2326434 ClOlt1493 4T4 = CEPT Tel
49、ecom 6.2. Terminal Addressing/Selective Calling TCAC S 10.1 E Page 9 That where a number of terminais of the same or different type(s) are supported on the same ISDN access, selective calling of individual terminals is supported by the following supplementary services: - Direct Dialling In (DDI) - Multiple Subscriber Number (MSN) - Sub-Addressing (SUB) From a functional viewpoint all three can be regarded as achieving the same effect. However DDI is part of the numbering scheme and its use must conform to the rules of the numbering scheme. Sub-addressing is not part of the numb
