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Cisco ONS 15454 DWDM Installation and Operations Guide, R6.0
August 2005
Chapter 21 Timing Reference
21.3 Synchronization Status Messaging
ST2 3 Stratum 2
ST3 4 Stratum 3
SMC 5 SONET minimum clock
ST4 6 Stratum 4
DUS 7 Do not use for timing synchronization
RES — Reserved; quality level set by user
Table 21-2 SSM Generation 2 Message Set
Message Quality Description
PRS 1 Primary reference source—Stratum 1
STU 2 Synchronization traceability unknown
ST2 3 Stratum 2
TNC 4 Transit node clock
ST3E 5 Stratum 3E
ST3 6 Stratum 3
SMC 7 SONET minimum clock
ST4 8 Stratum 4
DUS 9 Do not use for timing synchronization
RES — Reserved; quality level set by user
Table 21-1 SSM Generation 1 Message Set (continued)
Message Quality Description