Thanks @m84029462

m84029462_I learn below from a case, though i am not sure about this.

Can you please share the icase with us ?

1. http://3ms.huawei.com/icase/#!icase/workflow/viewCase.html?casecode=TC0000018440&caseop=true&searchkey=FAQ-The,LT1,Alarm,Reported,During,Clock,Switching,1,clock&sid=1472460450346

Copy the code

Please have the icase file....

What are the clock modes ?

There are three clock running modes: tracing mode, holdover mode and free-run mode.
1. By default, the free-run mode is used, that is, the system clock is the clock source.
2. After a clock source is manually configured, the clock enters the tracing mode.
3. When all clock sources in the priority table are lost or report alarms, the system clock traces the internal clock source and the clock module enters the holdover mode, that is, the historical phase-locked data recorded by the DSP is recovered from the RAM for phase-locking based on experience

1. m80009298 _What are the clock modes ?@m80009298

Copy the code

What are the clock protection modes? It would be very kind if any expert let us know.....

There are three clock protection modes: clock priority mode, standard SSM mode and extended SSM mode.

Clock priority mode:
This mode is the default clock protection mode. Clock sources are protected based on the configured clock source priority table. When a clock source with higher priority is lost, another clock source with lower priority is used.

Standard SSM mode:
In this mode, the cross-connect clock module extracts the S1 byte of the clock source in the clock source priority table when the SSM protocol is enabled. This S1 byte is used to configure clock source protection. If two clock sources are of the same quality, choose the clock source depending on their priorities.

Extended SSM mode:
In this mode, the most significant four bits of the S1 byte that are not defined by the ITU-T are used to transmit the clock ID based on the standard SSM mode. This is good to avoid clock loops in some scenarios. The protection mode in this SSM mode is the same as that in the standard SSM mode.

Dear @m80006077 , Thanks a lot for sharing with us this kind of information....

you are most welcome.

Is there any mode difference for Holdover Mode ?

Hasan_Rafi : There are three clock running modes: tracing mode, holdover mode and free-run mode.

There are two holdover modes: common holdover and permanent holdover

[at]user_2791329[/at] : Is there any mode difference for Holdover Mode ?