H3C S9500 Series Command Manual page 1818

Command Manual – Clock Module
H3C S9500 Series Routing Switches
1.1.6 clock ssm
Syntax
clock ssm { dnu | lnc | p rc | sets | tnc | unknown } source source-no
undo clock ssm source source-no
View
System view
Parameters
dnu: Should be used for synchronization (DNU).
lnc: G.812 local node clock signal (LNC).
prc:G.811 clock signal (PRC).
sets: Clock source signal of SDH equipment (SETS).
tnc: G.812 transfer node clock signal (TNC).
unknown: The quality of synchronization is unknown.
source-no: Number of clock source, ranging from 1 to 18.
Description
Use the clock ssm command to set the SSM level of each clock source.
Use the undo clock ssm command to restore the SSM level of each clock source to
the default value. By default, the SSM level of each clock source is unknown (the
quality of synchronization is unknown).
Note that:
For line clock source, the set SSM level is the SSM level of the clock source.
For Bits clock source, if the input signal is 2048 kbps (E1) and SSM is engaged in
control, the SSM level of the clock source is the SSM level extracted from the input
signal, and the set SSM level is neglected.
For Bits clock source, if the input signal is 2048kHz signal, or the input signal is
2048kbits/s signal but SSM is not engaged in control, the set SSM level is the SSM
level of the clock source.
SSM means Synchronization Status Marker, which is also referred to as synchronous
quality information. It is used to indicate the level of synchronous timing signal in
synchronous timing transfer link. For line clock sources, SSM level is extracted by the
interface card and reported to the SRPU, and then the SRPU sets the SSM level of the
line clock source for the clock module.
When the clock module is powered on, the default SSM level of all clock sources is
unknown (the quality of synchronization is unknown). From high to low, the order of
SSM levels is: PRC > TNC > LNC > SETS > unknown > DNU. If the SSM level of a
Chapter 1 Clock Module Commands
1-6