1、ETSI I ECHNICAL REPORT ETR 033 July 1992 Source: ETSI TC-NA Reference: DTR/NA-2 1 1 03 UDC: 621.395 Key words: Interconnection, numbering, network Network Aspects (NA); Numbering plans for the interconnection of virtual private networks and public networks ETSI European Telecommunications Standards
2、Institute ETSI Secretariat Postal address: 06921 Sophia Antipolis Cedex - FRANCE Office address: Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE Tel.: + 33 92 94 42 O0 - Fax: + 33 93 65 47 16 - Tlx: 470 040 F European Telecommunications Standards Institute 1 992. All rights reserved. No pa
3、rt may be reproduced or used except as authorised by contract or other written permission. The Copyright and the foregoing restriction on reproduction and use extend to all media in which the information may be embodied. - ETSI ETRu033 92 W 3400855 005323b 089 mi Page 2 ETR 033:1992 Whilst every car
4、e has been taken in the preparation and publication of this document, errors in content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to “ETSI Standards Management Dept.“ at the address shown on the title page. . ETSI ETR*O33 92 3400855 0053237 TL
5、5 m Page 3 ETR 033:1992 Contents Foreword . 5 1 2 3 4 5 6 7 8 9 10 11 12 Scope and introduction 7 References . 8 Numbering plans for VPN . 8 Abbreviations and definitions 8 4.1 Abbreviations 8 4.2 Definitions . 9 Private numbers 9 Private numbers used together with public location dependent numbers
6、. 10 6.1 Without DDI 10 6.2 With DDI via location dependent numbers 11 Private numbers used together with public location independent numbers . 14 7.1 Without DDI 14 7.2 With DDI via location dependent numbers 15 7.3 With DDI via location independent numbers . 17 Partial ISDN numbers 20 Merging inte
7、rnal numbers . 23 Members of more than one VPN . 24 Managing the numbering plan . 24 Evaluation 24 Annex A: . 25 An evaluation of some aspects that should be considered when implementing numrering plans for VPN . 25 Annex B: 27 A summary of the evaluation of different methods for the implementation
8、of numbering plans for VPN . 27 . - ETSI ETRx033 92 m 3400855 0053238 951 m Page 4 ETR 033:1992 Blank page Page 5 ETR 033:1992 Foreword ETSI Technical Reports (ETRs) are informative documents resulting from ETSI studies which are not appropriate for European Telecommunication Standard (ETS) or lnter
9、im-European Telecommunication Standard (I-ETS) status. An ETR may be used to publish material which is either of an informative nature, relating to the use or application of ETSs or I-ETSs, or which is immature and not yet suitable for formal adoption as an ETS or I-ETS. This ETR has been produced b
10、y the Network Aspects (NA) Technical Committee of the European Telecommunications Standards Institute (ETSI). Previous page is blank ETSI ETR*033 92 3900855 0053240 50T Page 6 ETR 033:1992 Blank page ETSI ETRx033 92 = 3400855 0053243 446 I ISDN subsc. exchange PTNX1 . - - - - - - Page 7 ETR 033: 199
11、2 ISDN subsc. ISDN exchange subscriber exchange -1 - - - - - _ _ -_ - PTNXZ PTNX3 1 Scope and introduction I This ETR describes the translation mechanisms of a public ISDN that supports private numbers as defined by the authority of a Virtual Private telecommunication Network (VPN). The ETR shows, o
12、n the basis of examples, solutions for selecting users connected to different exchanges (PTNXs) of the VPN, as well as stand-alone users, see figure 1. I The application of this ETR, or part of it, to virtual private networks as defined and implemented in the context of an intelligent network requir
13、es further study. I PTNX4 It is assumed that the numbering functionality of VPN is the stage 1 description of support of private numbering plan (called private numbering plan in CCIlT) elaborated by CCIlT Study Group I (reference Com I-R20). PTNXS I A VPN covers telecommunication within an organisat
14、ion/administration connected to many ISDN subscriber exchanges in one or more countries. Figure 1 shows the components of VPN. NOTE: X means individual 2B + D or 30 B + D centre connection. Figure 1: Components of VPN The organisation/administration may cover: - a company internal network with divis
15、ions scattered around the country/world; - a public department/organisation with regional divisions within a country; - a group of individuals; - a combination of one or more ot the above mentioned groups. Packet switching data communication is outside the scope of this ETR. For VPN internal data co
16、mmunication between CCIlT Recommendation X.25 ill terminals it is necessary for the Numbering Plan Identifier (NPI) field of X.25 to be implemented within pubic data networks. NOTE: The digit strings shown within the VPN internal numbering plan tables in the following sections have been included to
17、illustrate each scenario covered, and should therefore be viewed as indicative only. ETSI ETRr033 72 m 3400855 0053242 382 m Page 8 ETR 033: 1992 2 References 1 I CCITT Recommendation X.25: “Interface between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) for terminals op
18、erating in the packet mode and connected to public data networks by dedicated circuit“. 21 CCIlT Recommendation E.164: “Numbering plan for the ISDN era“. i31 ETS 300 1 89: “Private Telecommunications Network (PTN); Addressing“ (ECMA-155). 3 Numbering plans for VPN Three different principles for allo
19、cation of numbers to VPN have been identified. a) private numbers used together with public location dependent numbers; b) private numbers used together with public location dependent and location independent numbers; c) partial ISDN numbers (see CCITT Recommendation E.164 21). Partial ISDN numbers
20、are VPN-internal numbers forming the end of the ISDN number. Use of the full ISDN number for VPN internal calls is for further study. All the principles can be realised with DDI, but only a) and b) can be realised without. Within VPN it is possible to combine the use of private and public numbers, e
21、specially the combination of private and public location independent numbers. 4 Abbreviations and definitions 4.1 Abbreviations cc Country Code DDI Direct Dialling In ECMA European Computer Manufacturers Association ILDN Internal Location Dependent Number ILIN Internal Location Independent Number IS
22、DN Integrated Services Digital Network ISPBX Integrated Services Private Branch exchange LDNSN Location Dependent National Significant Number LDNSN 1 Location Dependent National Significant Number with DDI LINSN Location Independent National Significant Number LINSN1 Location Independent National Si
23、gnificant Number with DDI NDC National Destination Code, reference CCITT Recommendation E. 1 64 2 NPI Numbering Plan Identifier ETSI ETRx033 92 m 3400855 0053243 219 m Location dependent nunbers PLDN PLIN PTN PTNX Location independent numbers Page 9 ETR 033: 1992 Private Location Dependent Number Pr
24、ivate Location Independent Number Private Telecommunication Network Private Telecommunication Network exchange. A PTNX may be represented by an ISPBX, or by equipment which is physically part of the equipment of an ISDN SN Subscriber Num ber VPN Virtual Private Network 4.2 Definitions Public locatio
25、n independent number: a directory number that can be used to reach a called user wherever he is located, limited only by the capability of the networks involved. (From a numbering point of view the public location independent number could be a universal personal telecommunication number or freephone
26、 number). Private location independent number: a number within a VPN excluding partial ISDN numbers, that can be used to reach a called user wherever he is located within the VPN, limited only by the capability of the networks involved. 5 Private numbers Private numbers may have a different structur
27、e and significance than public numbers. The numbers may be location dependent or location independent. Within VPN, the location dependent numbers can either be allocated physically to each PTNX , .e. contiguous numbering, or be allocated individually to members of VPN .e. non-contiguous numbering. T
28、he structure of private numbers can be illustrated as in figure 2: I Private nhrs I PTNX1 u(X PTNX1 200,202. . II 2 4XX II 2 201,405, . Figure 2 The private numbers are outside the public numbering plan (see ETS 300 189 131). This ETR encompasses the private numbering plan and unknown numbering plan
29、 of the ECMA standard ETS 300 189 131. All the examples in this report are based on contiguous numbering, but the description and comments are valid, irrespective of how the internal numbering for the location dependent numbers is done. Use of non contiguous numbering makes stronger demands on the V
30、PN than contiguous numbering. Page 10 ETR 033:1992 6 Private numbers used together with public location dependent numbers 6.1 Without DDI Each member of a national or international VPN is allocated a minimum of one private location dependent number (see NOTE). The network is allocated one or more pu
31、blic location dependent numbers depending on how many PTNXs it includes. The public numbers will be the PTNXs main numbers, and as such common for many members of VPN. NOTE: In addition some or all members may be allocated private location independent numbers. The number structure is as follows: + P
32、ublic location dependent number without DDI NOTE 1: NOTE 2: Private numbers The structure of LDNSN is NDC + SN as described in CCITT Recommendation E.164 21. The structure of private numbers is given in ETC 300 189 31. Figure 3 The telecommunication authority assigns LDNSN and the VPN-owner assigns
33、PLDN and PLIN. The maximum length of the public location dependent numbers is 15 digits post time T and 12 digits pre time T. Figure4 shows the relation between VPN numbers and public location dependent numbers without DDI. * PLDN :PLIN! *. : * .I Location independent numbers e Figure 4: Relation be
34、tween VPN numbers and public location dependent numbers without DDI The length of the private numbers is decided by the VPN-owner, and can either be constant within VPN or differ from PTNX to PTNX or between individual members of VPN. With different number length from PTNX to PTNX it is normally ass
35、umed that the length can unambiguously be decided by analysing the most significant digits of PLDN. The private location dependent numbers and the private location independent numbers can be separated in the same way. An example of a VPN numbering plan based on private numbers without DDI is given i
36、n table 1. Page 11 ETR 033:1992 Table 1: Example of a VPN numbering plan based on private numbers without DDI VPN internal numbering plan O 1 xxx 2xx 3xx 4x 5xx 6-8 9 I The number indicates VPN external call (NOTE 1) PLDN, PTNX1 PLDN, PTNX2 PLDN, PTNX3 PLIN, (PLDN) (NOTE 2) PLIN (PLDN) (NOTE 2) Rese
37、rve Call to operator (NOTE 1) NOTE 1 : Prefixes and access codes are outside the numbering plan. NOTE 2: (PLDN) indicates that each PLIN terminates on a PLDN. PLDN can be used between all members of VPN, but only the members with PLIN can maintain their internal numbers without administrative interf
38、erence when moving between PTNXs. In the example the first digit 4 and 5 indicates that it is a location independent number, and that the database of the telecommunication administration shall be inquired to locate the actual member. PLIN is translated to the main number of the actual PTNX (LDNSN) a
39、nd the correct private number (PLDN). When using PLDN, translation will take place for VPN-internal calls outside the own PTNX. PLDN is translated to the actual LDNSN and PLDN is forwarded to the terminating PTNX. For PTNX-internai calls PLDN can be used without translation. 6.2 With DDI via locatio
40、n dependent numbers Each member of a national or international VPN is allocated a minimum of one number. Members with DDI are allocated one public location dependent number (DDI-number), while members without DDI are allocated one private location dependent number (see NOTE). The network is allocate
41、d one or more public location dependent numbers (main numbers), depending on how many PTNXs and basic accesses it includes. Each main number is common for many members. NOTE: In addition some or all members may be allocated private location independent numbers. ETSI ETR*O33 92 m 3400855 O053246 T28
42、Page 12 ETR 033:1992 The number structure is shown in figure 5: + -1 Public location dependent number without DDI + -1 Public location dependent number with DDI - ILDN PLDN (NOTE 2) Private numbers NOTE 1: The structure of LDNSN is NDC + SN as described in CCITT Recommendation E.164 i21. NOTE 2: The
43、 structure of private numbers is given in ETS 300 189 131. Figure 5 The telecommunication authority assigns LDNSN, and the VPN-owner assigns PLDN and PLIN and organises ILDN. The maximum length of the public location dependent numbers is 15 digits post time T and 12 digits pre time T. Figure 6 shows
44、 the relation between VPN numbers and public location dependent numbers with DDI. b b 0 b b b b ISDN numbers *.* . 1. a. Location independent numbers Figure 6: Relation between VPN numbers and public location dependent numbers ETSI ETRa033 72 3400855 0053247 764 Page 13 ETR 033:1992 The length of th
45、e private numbers is decided by the VPN-owner, and can either be constant within VPN, or differ from PTNX to PTNX or between individual members of VPN. With different number length from PTNX to PTNX it is normally assumed that the length can unambiguously be decided by analysing the most significant
46、 digits of PLDN. The private location dependent numbers and the private location independent numbers can be separated in the same way. The VPN-internal numbering plan can be based upon the use of: a) PLDN and PLIN in parallel with ILDN; b) ILDN and PLIN, as shown in table 3; c) ILDN, PLDN and PLIN,
47、as shown in table 2. Table 2: Example of a VPN numbering plan with public location dependent numbers with DDI to one of the PTNXs VPN internal numbering plan O 1 xxx 2xx 3xx 4x 5xx 6-8 9 The number indicates VPN external call (NOTE 1) PLDN, PTNXl PLDN, PTNX2 PLDN, PTNX3 PLIN (ILDN or PLDN) (NOTE 2)
48、PLIN (ILDN or PLDN) (NOTE 2) Reserve Call to operator (NOTE 1) NOTE 1 : Prefixes and access codes are outside the numbering plan. NOTE 2: (ILDN or PLDN) indicates that each PLIN terminates on a ILDN or PLDN. ILDN or PLDN can normally be used between all members of VPN, but only the members with PLIN
49、 can maintain their internal numbers without administrative interference, when moving between PTNXs. With DDI it is not necessary that all members have PLDN. Each member must, however, have one location dependent internal number, either a public (ILDN) or a private (PLDN) number. If ILDN is to be used internally for calls to more than one PTNX, a conflict situation due to merging ILDNs may arise. Clause 9 describes three methods that can be used for co-ordination of public internal number series to avoid merging ILDNs.
