H3C Technologies H3C SR8800 - Manual (Page 99)

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Configuring SSM levels for the reference sources
Follow these rules to manually set the SSM level for the clock source:
• For the line clock source, the SSM level configured is that of the clock source.
• For Bits clock source, if the input signal is a 2048 kbps (E1) signal and the clock forcessm off source
source-number command is executed, the clock source adopts the SSM level derived from the input
signals and the SSM configured is omitted.
• For Bits clock source, if the input signal is a 2048 kHz signal or a 2048 kbps signal and the clock
forcesssm on source source-number command is executed, the clock source adopts the SSM level
configured.
To set the SSM levels:
Step Command Remarks
1. Enter system view. system-view N/A
2. Set the SSM levels of the
reference source.
clock ssm { dnu | lnc | prc | sets |
tnc | unknown } source
source-number
unknown by default.
NOTE:
•
The reference source with the SSM level DNU cannot be used as a clock source. Therefore, it does not
participate in clock source switch when the clock monitoring module works in auto mode.
• After you set the SSM levels of the reference source, it takes a period of time for device response. In this
case, you can check whether your configuration takes effect through the display clock ssm-level
command and the logging information.
Activating/deactivating SSM
Whether the SSM levels are obtained through clock signals or configured manually, you have to activate
or deactivate them before they can take effect.
• When SSM is activated, the reference source level is decided by the SMM level first and then the
priority of the reference source in automatic clock source selection.
• When SSM is not activated, you can still set and view the SSM levels, but they are ignored and the
reference source level is decided by the priority of the reference source in automatic clock source
selection.
To activate or deactivate SSM:
Step Command Remarks
1. Enter system view. system-view N/A
2. Activate/deactivate SSM. clock ssmcontrol { on | off }
Optional.
By default, SSM is deactivated.
Setting the input port of the line clock (LPU port)
To set the input port of the line clock (LPU port):