標準號：SIS SS-NET 2-1989
中文標準名稱：對使用CCITT推薦X．25 （1984）連接到電路交換公共數據網絡的數據終端設備的審批要求
英文標準名稱：Approval requirements for data terminal equipment to connect to packet switched public data networks using CCITT Recommendation X.25 (1984) interface
發布日期：1989/9/13 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：This NET details the technical requirements for connection of packet mode DTEs to dedicated circuit interfaces of PSPDNs using CCITT Recommendation X.25 (1984) [1], excluding LAP, offered by an Administration.Note - The physical, link and packet level tests detailed in this NET are suitable for testing of DTEs for connection to CCITT Recommendation X.25 (1980) [2] PSPDN. (See Appendix II for additional information.)The objective of this NET is to minimise, to an acceptable level, disturbance to the PSPDN and to improve the probability of interworking between a PSPDN and terminal equipment so that calls can be routed successfully through the network but without any guarantee of terminal to terminal operation.To achieve this objective, this NET describes generalised tests to be carried out against the physical, link and packet level requirements of a CCITT Recommendation X.25 DTE implementation. A DTE which satisfies the relevant technical requirements of this document and any other DTE which is of the same DTE type may be connected to every PSPDN, use any of the essential (E) facilities and invoke any of the provided additional (A) facilities as given in CCITT Recommendation X.2 (1984) [3]. Where optional user facilities which are not included in this document are supported by the network, a DTE invoking such facilities will be subject to additional tests by certain Administrations. The relevant tests will be included as a supplement to the present NET. The subject of integrated modems is outside the scope of this NET.Certain Administrations do not apply the technical requirements in Clauses 9 and 10 (the link level and packet level requirements) before a DTE is given permission to connect to their PSPDNs. These Administrations are listed in Annex D.Note - It is nevertheless important that a DTE should behave as stated in Clauses 9 and 10, otherwise it may experience service difficulties when connected to a PSPDN.