M120 External Clock Interface Ports On The Craft Interface; Table 8: External Clock Leds On The M120 Craft Interface - Juniper M120 Hardware Manual

M120 Multiservice Edge Router Hardware Guide
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M120 External Clock Interface Ports on the Craft Interface

16
Two bi-color LEDs in the lower left and right corners of each port indicate port status.
The LED on the lower left as you face the craft interface indicates whether an external
clock source is present. The LED on the lower right as you face the craft interface indicates
if there is a fault. Table 8 on page 16

Table 8: External Clock LEDs on the M120 Craft Interface

Label Color
A Green
–
B Yellow
(Fault LED)
–
M120 Craft Interface Description on page 11
Maintaining the M120 Host Subsystem on page 266
Replacing the M120 Craft Interface on page 184
Two external clock ports EXT CLOCK
you to connect the router's internal Stratum 3 clock to an external reference clock source
with an RJ-45 cable. Using the router's software, you can configure the internal Stratum
3 clock to synchronize with an external Building Integrated Timing System (BITS) or SDH
Equipment Timing Source (SETS) timing source by including a clock synchronization
statement at the
[edit chassis]
NOTE: Refer to the, Junos OS Administration Library for configuration
information.
The ports are labeled
EXT CLOCK
clock inputs with T1 or E1 reference clocks.
Two bi-color LEDs in the lower left and right corners of each port indicate port status.
The LED on the lower left as you face the craft interface indicates whether an external
clock source is present. The LED on the lower right as you face the craft interface indicates
if there is a fault. Table 8 on page 16
describes the external clock port LEDs,
State Description
On steadily External clock source is plugged into the port,
physical signal is present.
Off No external clock source is plugged into the port, no
physical signal is present.
On steadily Fault condition; external reference clock frequency
is out of the tolerance threshold deviation of 10
parts-per-million (PPM).
Off External clock signal is validated or no external clock
source is plugged into the port.
to the right of the craft interface alarm LEDs enable
hierarchy level.
and . They accept two RJ-45 connectors for external
A B
describes the external clock port LEDs,
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