H3C Technologies H3C SR8800 - Manual (Page 98)

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Configuring reference source priority
In auto mode, the clock monitoring module selects and switches to a reference source with a higher
priority based on SSM level and reference source priority. The smaller the value, the higher the priority.
To configure reference source priority:
Step Command Remarks
1. Enter system view. system-view N/A
2. Configure the reference
source priority. clock priority value source
source-number
255 by default.
Configuring SSM for reference sources
Setting the ways of deriving SSM level
You can use the following two ways to derive SSM level:
• For bits clock source, SSM level can be derived from the interface card and reported to the SRPU,
which then sends the SSM level to the clock monitoring module.
• Or you can configure SSM level as needed, as shown in the following table:
To set the ways of deriving SSM level:
Step Command Remarks
1. Enter system view. system-view N/A
2. Set the ways to derive SSM
level. clock forcessm { on | off } source
source-number
Optional.
By default, no SSM level is derived
from any clock source, which
means the SSM level is set by
users.
Setting the bit position for transmitting bits clock source
information
The bit position for transmitting Bits clock source information can be configured as sa4, sa5, sa6, sa7
and sa8. They are 5 bits in timeslot 0 of the even frame in a multi-frame as specified by ITU-TG.704 CRC4.
You can choose one from the five bits to carry SSM information.
To set the bit for transmitting Bits clock source information:
Step Command Remarks
1. Enter system view. system-view N/A
2. Set the bit for transmitting the
Bits clock source information. clock sa-bit { sa4 | sa5 | sa6 | sa7
| sa8 } source source-number Optional.
sa4 by default.