Network and Customer Installation Interfaces – Broadband ISDN: Common Criteria
|Publication Date:||1 January 2003|
This standard provides the physical layer common criteria for Broadband Integrated Services Digital Network (BISDN) signals appearing at Customer Installation (CI) interfaces and at the Network Interface (NI). The term User-Network Interface (UNI) has been used in various fora, including Committee T1, to refer either to the interface between the CI and the network (i.e., the NI) or the collection of interfaces appearing on the customer premises, including the NI. The term UNI will henceforth be used in this standard to specify characteristics that apply to both the complete set of CI interfaces and the NI.
B-ISDN is implemented by mapping Asynchronous Transfer Mode (ATM) signals into the payloads of the physical layers of various transport technologies. The B-ISDN physical layer is divided into two sub-layers: the Transmission Convergence (TC) sub-layer and the Physical Medium Dependent (PMD) sub-layer. The previous edition of this standard (T1.646-1995) addressed both the TC and PMD sub-layers of the covered transmission technologies. With this revision, the PMD sub-layer requirements and the TC sub-layer requirements that are specific to each transmission technology are removed to a standard associated with that technology. This standard retains the TC sub-layer requirements that are independent of any particular technology or rate. With this revision, the DS1 requirements are removed to T1.403.03-200x, the DS3 requirements to T1.404.01-2000, and the SONET requirements to T1.416.04-2005.
This standard specifically addresses UNI reference configuration, maintenance functionality, and other necessary criteria for compliance with the physical specification at a UNI. It defines such characteristics and technical criteria at four recognized reference points of the B-ISDN reference configuration, namely the UB, TB, SB, and SSB reference points. Compliance with this standard is intended to ensure compatibility at a B-ISDN UNI and should not be construed as a constraint on the internal operations of the network or CI equipment.
This standard provides a fundamental definition of a UNI and is to be used in conjunction with other standards on higher layer (e.g., ATM layer) specifications to provide a complete technical description of a B-ISDN UNI. B-ISDN is described in the ITU-T (formerly CCITT) I-series recommendations (see Annex A).
The provisions of this standard are intended to be consistent with applicable requirements concerning safety and environmental conditions.