Network and Customer Installation Interfaces - SONET Physical Layer Interface and Mapping Specifications for ATM Applications
|Publication Date:||1 January 2005|
This standard provides the physical layer (Layer 1) specifications for SONET User-Network Interfaces (UNIs) that are used to transport asynchronous transfer mode (ATM) cells in the SONET 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).
SONET-ATM interfaces include, but are not limited to, SONET 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 T1.646-2003.
This standard addresses synchronization, line code, framing format, ATM mapping, and connectors associated with the SONET-ATM interface. Specifications for processing the header error check (HEC) and for maintenance and performance monitoring of a SONET signal that transports ATM cells are also provided, by reference, in this document.
All requirements are applicable at all UNIs unless specifically identified as being applicable to the NI or the Ia and Ib interfaces. T1.646-2003 defines interface points Ia and Ib as physical locations designating the boundaries between functional groupings. Interface point Ia is adjacent to the B-TE, B-NT2, and BNT1 on their network side; interface point Ib is adjacent to the B-NT2 and B-NT1 on their user side (refer to T1.646-2003 for a graphical representation).
This standard is a revision of the portions of T1.646-1995 and T1.646a-1997 that refer, in the generic sense, to the transport of ATM cells in the SONET payload. Portions of T1.646-1995 that relate specifically to the use of SONET transport for broadband integrated services digital network (B-ISDN) applications will remain in T1.646-2003. 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. By publication of this standard, no position is taken with respect to the validity of this claim or of any patent rights in connection therewith. The patent holder has, however, filed a statement of willingness to grant a license under these rights on reasonable and nondiscriminatory terms and conditions to applicants desiring to obtain such a license. Details may be obtained from the publisher.