Network and Customer Installation Interfaces – DS1 Physical Layer Interface and Mapping Specification for ATM Applications
|Publication Date:||1 January 2002|
This standard provides the physical layer (Layer 1) specifications for DS1 User-Network Interfaces (UNIs) that are used to transport asynchronous transfer mode (ATM) cells in the DS1 payload. The term User-Network Interface (UNI) is used in this standard to refer to both the Network Interface (NI) and interfaces within the Customer Installation (CI).
DS1-ATM interfaces include, but are not limited to, DS1 access to a Broadband - Integrated Services Digital Network (B-ISDN). For information concerning the four B-ISDN reference points (UB, TB, SB, and SSB), see T1.646-1995.
This standard addresses synchronization, line code, framing format, ATM mapping, and connectors associated with the DS1-ATM interface. All requirements are applicable at all UNIs unless specifically identified as being applicable to the NI or the IA and IB interfaces. T1.646-1995 defines interface points IA and IB as physical locations designating the boundary of functional groupings. Interface point IA is adjacent to the B-TE, B-NTA, and B-NT1 on their network side; interface point IB is adjacent to the B-NT2 and B-NT1 on their user side (refer to figures 7 and 8 of T1.646-1995 for a graphical representation.
Specifications for processing the header error check (HEC) and for maintenance and performance monitoring of a DS1 signal that transports ATM cells are also provided, by reference, in this document.
This standard is a revision of the portions of T1.646-1995 that refer, in the generic sense, to the transport of ATM cells in the DS1 payload. Portions of T1.646-1995 that relate specifically to the use of DS1 transport for broadband integrated services digital network (B-ISDN) applications will remain in the revision of T1.646- 1995.The provisions of this standard are intended to be consistent with applicable requirements concerning safety and environmental conditions.
NOTE- The user's attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights.
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