1、 STD*ITU-T RECMN 1-259.L-ENGL L97b 4Bb2591 Ob21421 499 D INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU 1.259.1 (07/96) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Service capabilities - Supplementary services in ISDN Screening supplementary services: A
2、ddress screening (ADS) ITU-T Recommendation 1.259.1 (Previously CCITT Recommendations) STD-ITU-T RECMN 1-259-L-ENGL L97b i8b2591 ObZLi22 325 M ITU-T - I SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology Description of ISDNs General modelling methods Telecommuni
3、cation network and service attributes General description of asynchronous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN SERVICE CAP AB I LITI ES I. 1 00-1.1 99 1.110-1.119 I. 120-1.1 29 1.1 30-1.139 I. 140-1.1 49 1
4、.150-1.199 1.200-1.299 1.200-1.209 1.21 0-1.21 9 I .220-1.229 1.230-1.239 Teleservices supported by an ISDN 1.240-1.249 1.250-1.2 1.300-1.399 OVERALL NETWORK ASPECTS AND FUNCTIONS Network functional principles Reference models Numbering, addressing and routing Connection types Performance objectives
5、 Protocol layer requirements General network requirements and functions Application of I-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing interfaces Aspects of ISDN affec
6、ting terminal requirements ISDN USER-NETWORK INTERFACES INTERNETWORK INTER FACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Management of ATM equipment 1.310-1.319 I .320-1.329 1.330-1.339 1.340-1.349 1.350-1.359 1.360-1.369 1.370-1.399 1.400-1.499 1.420-1.429 1.430-1.439 1.440-1.
7、449 I .450-1.459 1.460-1.469 I .47 or a set identified by a Recommendation 1.259.1 (07196) 1 STD-ITU-T RECMN 1.Z59.L-ENGL L77b = 48b257L Ob21428 843 GA of geographically distinct UNIS at the TB reference point which are the recipients of a multicast communication. 2.2.2 group address: GA represents
8、the set of IAS that identify the destinations of a multicast communication (Recommendation F.812 i). It can only be a DA. It is an ISDN number. 2.2.3 group screen: It is the set of exclusively GAS used for screening. 2.2.4 individual address: An IA identifies a particular source or destination UNI a
9、t the TB reference point of a point-to-point data transfer between users. It is an ISDN number. 2.2.5 individual screen: It is a set of exclusively IAS used for screening. 2.2.6 source address: It identifies a particular interface at the TB reference point which originates a point-to-point data tran
10、sfer between two users. It is an IA. 2.3 Symbols and abbreviations For the purposes of this Recommendation, the following abbreviations are used. ADS B-ISDN CLAI DA IA ISDN GA SA UNI Address Screening Broadband Integrated Services Digital Network Connectionless Access Interface Destination Address I
11、ndividual Address Integrated Services Digital Network Group Address Source Address User-Ne t work In terface 2.4 This ADS supplementary service applies to the BCDBS (see Recommendation F.812 i). It applies to both point-to-point and multicast communications supported by the service. It is offered at
12、 the CLAI (see Recommendation 1.364 3). Qualification on the applicability to telecommunication services 3 Procedures 3.1 Provision/withdrawal The ADS supplementary service (destination and source) is provided on a subscription basis. This subscription applies separately to each E. 164 number which
13、identifies a user. For each subscription, an individual and/or group screen is defined. It is a subscription option to specify whether: a) b) a screen acts positively (a match between the address received in the data unit and one of the addresses of the screen is required for acceptance/delivery); o
14、r negatively (a mismatch is required for acceptance/delivery). 2 Recommendation 1.259.1 (07/96) STD-ITU-T RECMN 1.259.L-ENGL L79b = 48b2591 Ob21429 78T 3.2 Normal procedures 3.2.1 Activation/deactivation/registration Activation through subscription. On demand is for further study. 3.2.2 Erasure Not
15、applicable. 3.2.3 Invocation and operation Invocation takes place implicitly when the user sends or receives a data unit over its UNI into or from the network. The network shall carry out internal checks to determine whether or not the transfer of a data unit is allowed when it enters the network (f
16、rom the source) and when it is ready to leave the network (towards the destination). 3.2.3.1 Actions at the originating side 3.2.3.1.1 The network has the ability to check the DA of each data unit sent from the source user against an individual screen. This individual screen associated with the subs
17、cribers SA shall consist of one and only one of the following: - - DA screening of individually addressed data units a list of “allowed individual DAS“; a list of “disallowed individual DAS“. If the individual screen consists of “allowed DAS“, and the DA of the data unit does not match one of these
18、addresses, the data unit shall not be delivered. If the individual screen consists of “allowed DAS“, and the DA of the data unit does match one of these addresses, the data unit shall be further processed by the network. If the individual screen consists of “disallowed DAS“, and the DA of the data u
19、nit does match one of these addresses, the data unit shall not be delivered. If the individual screen consists of “disallowed DAS“, and the DA of the data unit does not match one of these addresses, the data unit shall be further processed by the network. 3.2.3.1.2 The same procedure as in the above
20、 subclause is also maintained for GAS. In the case of user data units with a destination GA, the network shall perform the DA screening by checking the GA against the group screen of “allowed“ or “disallowed“ DAS. 3.2.3.2 Actions at the destination side DA screening of group addressed data units 3.2
21、.3.2.1 The network has the ability to check the SA of the user data unit to be delivered against the individual screen associated to the DA of that data unit. This individual screen shall consist of one and only one of the following: - - SA screening of individually and group addressed data units a
22、list of “allowed individual SAS“; or a list of “disallowed individual SAS“. If the individual screen consists of “allowed SAS“, and the SA of the data unit does not match one of the screen addresses, the data unit shall not be delivered. Recommendation 1.259.1 (07/96) 3 STD-ITU-T RECMN I*257.1-ENGL
23、177L E 48b257I1 Ob21430 4T1 E If the individual screen consists of “allowed SAS“, and the SA of the data unit does match one of the screen addresses, the data unit shall be further processed. If the individual screen consists of “disallowed SAS“, and the SA of the data unit does match one of the scr
24、een addresses, the data unit shall not be delivered. If the individual screen consists of “disallowed SAS“, and the SA of the data unit does not match one of the screen addresses, the data unit shall be further processed. In the case of group addressed data units, one or more of the UNIS associated
25、with the IAS represented by the GA may have SA screening invoked, such that data units from the specific SA are not allowed to be delivered to these UNI(s). In such a case, a copy of the data unit is not delivered to these UNI(s) where screening is invoked. A copy of the group addressed data unit sh
26、all be delivered to each UNI represented by the GA where screening does not apply or determines that delivery is allowed. 3.2.3.2.2 Multiple addresses and screens If a subscriber specifies one individual screen and one group screen, then the individual screen must be used for SA screening of individ
27、ual and group addressed data units and for DA screening of individually addressed data units, and the group screen must be used for DA screening of group addressed data units. If more than one ISDN number is assigned to the UNI of a subscriber, the subscriber can specify more than one individual scr
28、een and more than one group screen. If so, then: a) Each IA assigned to the UNI must be associated with one individual screen: it is used for destination ADS of individually addressed data units sent from that UNI and having that address as SA, and is also used for SA screening of data units intende
29、d for delivery to that UNI and having that address as DA. Each IA assigned to the UNI must be associated (if group addressing is applied) with one group screen, which is used for destination ADS of group addressed data units sent from that UNI and having that address as SA. Each GA that identifies t
30、he UNI must be associated with one individual screen, which is used for SA screening of group addressed data units intended for delivery to that UNI and having that address as DA. b) cl 3.3 Exceptional procedures For further study. 4 Network capability for charging It shall be possible to charge the
31、 subscriber for this service. Charging principles are outside the scope of this Recommendation. 5 Interworking requirements For further study. 6 For further study. Interaction with other supplementary services 4 Recommendation 1.259.1 (0796) 7 SDL description The actions when a data unit is received
32、 in the network c ler a UNI or when the network is prepar to send a data unit across a UNI are described in Figure 1. I Reception of a data I unit from a user over SA, DA - SA is allocated to Get screen associated to UNI source screening of a multicast communication where the X is one of the individ
33、ual addresses represented by the GA used for this multicast communication; the dotted arrows show associations of an address to the UNI and of addresses to screens, Pseudo-solid arrows represent the flow of the data unit. Solid arrows represent logical actions for ADS. as a source address; o o o 6 R
34、ecommendation 1.259.1 (07/96) Network User t User UNI DA screening - - - - - UNI I data unit 4 I I -_. 5 : - ! - L I l l I I I I I I I I I I l I l I I I l l I I I I l 0- Iscr a Gscr r TO 104680-95 FIGURE I. 1D.259.1 DA screening Recommendation 1.259.1 (07/96) 7 Iscr p Individual screen p Gscr q Grou
35、p screen q GAk Group Address k IAm Individual Address m ND allowedhot allowed DA Destination Address SA Source Address FIGURE I.2A.259.1 SA screening TO 104690-95 a Recommendation 1.259.1 (07/96) STD-ITU-T RECMN 1.259.L-ENGL 199b 48b259L 0622435 TA3 ieries A eries B eries C ieries D ieries E ;,ries
36、F Series G series H Series I Series J Series K Series L Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series V Series X Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression General telecommunication statistics General tari
37、ff principles Telephone network and ISDN Non-telephone telecommunication services Transmission systems and media Transmission of non-telephone signals Integrated services digital network Transmission of sound-programme and television signals Protection against interference Construction, installation
38、 and protection of cables and other elements of outside plant Maintenance: international transmission systems, telephone circuits, telegraphy facsimile and leased circuits Maintenance: international sound-programme and television transmission circuits Specifications of measuring equipment Telephone
39、transmission quality Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminal equipment and protocols for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Programming languages Printed in Switzerland Geneva, 1996
