ATIS 0900101.2013(S2023)

This revised standard describes synchronization interfaces for the North American digital telecommunications hierarchy.
Compliance with this standard is necessary to achieve satisfactory interworking of telecommunications networks. This revision
of the standard includes requirements on essential timing characteristics at synchronization interfaces. It introduces the
stratum 3E clock and performance characteristics; holdover characteristics for stratum 2, 3, and 3E clocks; and second generation Synchronization Status Message quality levels.