1、NET 1 First edition: 1988 TRAC TECHNICAL RECOMMENDATIONS APPLICATION COMMITTEE EUROPEAN TELECOMMUNICATION STANDARD Approval requirements for data terminal equipment to connect to circuit switched public data networks and leased circuits using CCITT Recommendation X.21 interface Conditions dagrmeiit
2、pour le raccordermit dquipements termnnirx de traitetmit de domes ir iui sseau public pour donnes ir commutatioii de circuits et aitx circitits lous utilisant li-iteiface djnie dans Ia Recommandation X.21 dir CCITT CEPT NET*% 8 232b4L4 O000002 3 NET 1 First edition: 1988 EUROPEAN TELECOMMUNICATION S
3、TANDARD Approval requirements for data terminal equipment to connect to circuit switched public data networks and leased circuits using CCITT Recommendation X.21 interface Conditions dagrment pour le raccordement dquipements terminaux de traitement de donnes un rseau public pour donnes commutation d
4、e circuits et aux circuits lous utilisant Iinteiface djinie dans In Recommandation X.21 du CCITT Published by: CEPT Liaison Ofice Seilerstrasse 22 CH-3008 Bern Telephone Facsimile: Telex : 911089 CEPT CH + 41 31 6220 81 + 41 3 1 62 20 78 CEPT NET*% 88 232b414 0000003 5 I NORMES EUROPENNES DE TLCOMMU
5、NICATION It is recognized, in the field of telecommunications within Europe, that there is a need to create common European standards for telecommunications equipment. Such harmonization would among other things facilitate cooperation between teecommunications equipment manufacturers and public tele
6、communications network operators, create a marketplace which naturally transcends that of national frontiers, enhance the efficiency of business and other communication across Europe to bring economic benefits, and help translate the vision of a united Europe into a working reality. In 1985 an initi
7、ative by the Conference of European Posts and Telecommunications Administrations (CEPT) resulted in the drafting of a Memorandum of Understanding (MOU) agreeing to the mutual recognition of results of tests of conformity to a technical specification which would be known as a Norme Europenne de Tlcom
8、munication (or NET). A list of signatories to the MOU is shown at the end of this introductory text. The signatories represent telecommunications Administrations in most countries in Western Europe, including EEC and EMCA administrations. In 1986 the European Community Council Directive 86/361/EEC l
9、aid down the principles of the initial stage of the mutual recognition of type approval for telecommunications terminal equipment. The Directive imposes the obligation on EC Member States to implement the recognition of tests to common conformity specifications. 1 NETs 1.1 include : - - Guiding prin
10、ciples under which a NET is written are the need to ensure essential requirements are met. These user safety insofar as this requirement is not covered by other legal instruments (e.g. Directive 73/23/EEC) safety of employees of public telecommunications network operators insofar as this requirement
11、 is not covered by other legal instruments (e.g. Directive 73/23/EEC) protection of public telecommunications networks from harm interworking of terminal equipment, in justified cases - - 1.2 Each NET constitutes part of a series of NETS prepared in.response to the MOU and the EC Directive 86/361. 1
12、.3 A NET details the requirements, and a specification of interface tests for conformance to those requirements, which a defined type of telecommunication terminal equipment is required to satisfy in order to obtain authorisation for connection of the equipment to a defined European telecommunicatio
13、ns network. The NET also includes, where appro- priate, requirements made necessary in a given State by historical network peculiarities. 1.4 The existence of a NET will make it possible for an accredited laboratory in a country whose Administration has signed the MOU, to carry out tests,specified i
14、n the NET, on terminal equipment submitted to it, and to issue a test report. On the basis of the report, a competent body may then issue a certificate of conformity to the NET. There may of course be cases where the laboratory itself is the competent certification authority. This certificate is the
15、n recognized as valid in all the other signatory countries, avoiding the need for the equipment to have to undergo the same tests over again each time approval is applied for in any of those countries. 1.5 The common reference point which a NET represents thus offers the opportunity of substantially
16、 reducing the complexity, length and cost of approval formalities. The operators of public networks are required to make reference to relevant NETs in public supply contracts. Manufacturers are thereby enabled to compete on a more equal technical basis in the supply of terminal equipment covered by
17、NETS. 2 TYPES OF NET The majority of NETs falls into one of the two categories: access NETs and terminal NETs. (a) Access NET Details of the technical characteristics (electrical, mechanical and access control protocol), to be offered by terminal equipment at the interface to a specific public telec
18、ommunications network are covered in an “access NET”. The objective of an access NET is to ensure no disturbance occurs to the network and to ensure interworking between network and terminal equipment so that calls can be routed successfully through the network (but without any guarantee of terminal
19、 to terminal operation). Indeed, since an access NET may have to serve a number of terminal NETs and applications which have not even been envisaged at present, it is important for the content not to include anything which is particular to a specific terminal or otherwise inhibiting to new developme
20、nts. fi - NET 1 III CEPT NETxL 88 232b414 0000004 7 m (b) Terminal NET The objective of a terminal NET is to ensure the end-to-end compatibility of a defined telecommunication service. The terminal NET should include any requirements which must be added to the corresponding access NET(s) to ensure e
21、nd-to-end communication. 3 DATE OF APPLICATION The date of application of a NET is that date at which the NET is recognized as being applicable, in the signatory Administrations, for the purposes of type approval, under the terms of Directive 86/36 l/EEC. 4 TRANSITION PERIOD 4.1 The transition perio
22、d commences at the date of application. The transition period is a period of flexibility during which there will be coexistence between the NET and any national requirements which relate to the Scope. After the expiry of the transition period the only applicable standard within the Scope for type ap
23、proval purposes will be that of the particular NET. The end of the transition period is fixed by TRAC as an objective for all signatory countries of the MOU. In some cases, however, for example when a new network has to be set up, all network operators may not be in a position to meet the objective.
24、 In such cases, the end of the transition period will be a date which is individual to the given country, and administrations will publish the projected date by which the end of the transition period can be achieved. 4.2 The following notes are offered as guidance on conformance testing of telecommu
25、nications equipment during the transition period: During the transition period, new telecommunications equipment offered by manufacturers under the Scope of this NET may be tested at a certified laboratory located within the signatory countries, either under this NET or under the existing national r
26、equirements, at the choice of the manufacturer. Testing under the NET rather than under the old requirements might offer the manufacturer the opportunity of a larger marketplace in which to sell the equipment. The transition period is also an opportunity for the public network operators to update th
27、eir network. However, a national approval authority would have the facility of refusing the approval of terminal equipment, for which a certificate of conformance to a NET had been issued, if the network were not yet compatible with the terminal equipment to be connected. 4.3 The following note is o
28、ffered as guidance on the supply and connection of telecommunications equipment that has already been approved either before application of this NET or during the transition period. After the application date of this NET, that is, during and after the transition period, the supply and connection of
29、equipment already approved to earlier standards may continue unless the national authority terminates the validity of approvals to earlier standards for whatever reason. Figure 1 is a diagrammatic representation of the above points. 5 APPROVAL PROCEDURES Details of national type approval procedures
30、are not contained within NETs, but are decided by national Administrations. 6 REQUIREMENTS TO BE SATISFIED The scope statement defines which types of equipment must meet the requirements of each NET. In addition, equipment may also have to satisfy the requirements in other NETS (as defined in their
31、scope statements) or, in the absence of harmonised NETs, one or more published national standards. In the absence of any requirements in other NETs or in published national standards, no additional tests may be sought by any approval authority in the countries whose Administration has signed the MOU
32、. _ 7 LEGAL BASIS OF THIS INTRODUCTORY TEXT This introductory text is provided for guidance, and to aid interpretation. Readers are advised that the legally binding document in the EC countries is the EEC Directive 86/361. CEPT NET*3 88 = 2326434 0000005 9 W 1 i (A) Conformance Test i ng Under old r
33、equirements - - - - Under this NET I Supply and Connection of Equipment Type- Approved before end of Transition Period Data of Application of NET FIGURE 1 End of Transition Period CEPT NET81 88 I 2326434 O000006 O = 8 SIGNATORIES OF THE MOU Austria Belgium Denmark Finland France F. R. Germany Greece
34、 Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom 9 AMENDMENTS TO A NET There may in the future be a need for amendments to a NET. Any amendments to a NET, or suspension or withdrawal of a NET, will be decided by the Technical Recommendations Appli
35、cation Committee (TRAC) and notified through appropriate channels including publication in the EC Oficial Journal. Errors detected within the text of a NET, or difficulties experienced with the application of a NET, should be reported to the following address: The Director, Ofice of the Secretariat,
36、 European Telecommunications Standards Institute, BP 52 F-06569 Valbonne Cedex The comments will be considered and acted upon by TRAC under an approved modifications procedure. Public consultation will take place in respect of all but the most urgent modifications to this NET. 10 THIS NET (NET 1) 10
37、.1 Adoption (TRAC), on the basis of a CEPT Recommendation, on the 9th March 1988 in Cambridge, United Kingdom. The content of NET 1 was adopted by a meeting of the Technical Recommendations Application Committee 10.2 Scope This NET (NET 1) details the requirements, and a specification of the interfa
38、ce tests for conformance to those requirements, of DTEs employing CCITT X.21 interfaces to circuit switched public data networks. The legal definition of the scope of this NET is provided in the section entitled “Scope” in the body of the NET. 10.3 Date of Application Transition Period. This NET app
39、lies from 1 July 1988 within those States represented in the list of Signatories, subject to the 10.4 Transition Period for this NET ThisNETis subject to a transition period of two years from the date ofapplication. After the expiry of the transition period on 30 June 1990 the only applicable standa
40、rd for type approval purposes within the Scope will be this NET. VI NET 1 (- I 5 5.1 5.2 5.3 5.4 5.4.1 5.4.2 5.4.3 5.4.4 5.4.5 8.1.1 CEPT NET*3 88 2326434 0000007 2 TABLE OF CONTENTS General Requirements Procedures Safety Requirements Electro magnetic compatibility (EMC) Requirements Testing Conditi
41、ons Environment for tesis Power Supply Limitations Test Equipment Requirements Accuracy on test measurements Tolerances on test components Network Interface Requirements Conformance Testing Conformance test suites Basic Interconnection tests Electrical characteristics 8.1.1.1 Tests for DTE Declared
42、by the Applicant as Conforming with CCITT Recommendation X.26 (V.10) 8.1.1.2 Tests for DTE Declared by the Applicant as Conforming with CCITT Recommendation X.27 (V.11) 8.1.2 Mechanical characteristics 8.1.3 Functional characteristics 8.1.4 Physical link control conditions 8.1.4.1 Steady binary cond
43、itions 8.1.4.2 Detection of steady binary conditions 8.1.4.3 Alignment of call control characters 8.2 Behaviour tests 8.2.1 Procedural tests 8.2.1.1 Call set upcalling side 8.2.1.2 Call set upcalled side 8.2.1.3 Clearing 8.2.1.4 Data transfer 8.2.2 Quiescent states 8.2.3 Time outs 8.2.3.1 Time out T
44、I 8.2.3.2 Time out T2 8.2.3.3 Time out T3A 8.2.3.4 Time out T3B 8.2.3.5 Time out T4B 8.2.3.6 Time out T5 8.2.3.1 Time out T6 8.2.4 Loops* 8.3 Capability tests 8.3.1 Facility tests* Annex A: National network requirements concerning X.21 i Al A2 A3 A4 A5 A6 AI A8 A9 Austria Denmark Finland France Fede
45、ral Republic of Germany Italy Norway Sweden United Kingdom Page 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 6 6 6 6 6 6 6 6 6 6 7 1 7 8 8 9 9 10 10 10 10 11 11 LI 12 12 12 12 12 12 13 13 14 15 16 17 18 19 20 21 1 CEPT NETUL 88 9 2326434 O000008 4 Appendix to Annex A: Conformance test suites for national nework re
46、quirements AA1 Austria AA2 Denmark AA3 Finland AA4 France AA5 Federal Republic of Germany AA6 Italy AA1 Norway AA8 Sweden AA9 United Kingdom Annex B: Information to be provided by the supplier to the accredited test laboratory Note - The test suite contains no tests for items marked -k. 29 29 30 31
47、32 33 51 52 53 54 56 CEPT NET*3 88 = 2326434 O000009 b W 1 Scope This NET contains requirements for the type approval of data terminal equipment employing CCITT Recom- mendation X.2 1 11 interface to circuit switched public data networks and leased circuits. The requirements are intended to ensure t
48、hat the service available to other users of public telecommunications systems is not interfered with, nor that any public system will be adversely affected. Safety requirements are included for protection of personnel operating the public telecommunications systems. This NET is applicable only if th
49、e relevant user classes of service are being provided by the Administration concerned. It does not impose any obligation on Administrations to provide any particular user class of service. Annexes (and their Appendices) to this specification are an integral part of this specification. 1.1 Although the title and scope of the NET appear to limit the application to cover only data terminal equipments, such equipment may cover applications other than data (for example, voice in Italy, voice and video in France, and public telephony service
