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Page 850 of 1536 Chapter 4 — Network Clocking
Example 5
Master Clock
Option 11
Central
Office
loop W
LD 60
TRCK PCK
Slave
LD 73:
PREF loop W
SREF loop A
Clocking off Master:
Tracking on Primary
loop W and loop A
used as a secondary
clock source.
Here, digital connections to the Central Office do exist. When a second
Digital loop from the CO becomes available, it can be used as a Secondary
Clock Source in case the Primary Source fails.
Slaves can track on each other as a secondary source since the chances of both
links to the Central Offices going down at the same time are minimal (very
unlikely).
All central offices must have a path back to the same stratum 1 source.
553-3011-315 Standard 10.0 May 1999
loop
A
Master Clock
Option 11
Central
Office
loop X
LD 60
TRCK PCK
Slave
LD 73:
PREF loop X
SREF loop A
Clocking off Master:
Tracking on Primary
loop X and loop A
used as a secondary
clock source.
loop
B
Master Clock
Option 11
Central
Office
loop Y
LD 60
TRCK PCK
Slave
LD 73:
PREF loop Y
SREF loop B
Clocking off Master:
Tracking on Primary
loop Y and loop B
used as a secondary
clock source.
553-7565.EPS