Configuring Clock Source Attributes for BMC Selection

This section describes how to configure clock source attributes used for BMC selection. The routers configured with clock source attributes can participate in BMC selection. A local clock on a 1588v2 router can also participate in BMC selection. The BMC algorithm helps 1588v2 routers to select a master clock. The master clock provides time signals for other routers over a 1588v2 network. 1588v2 routers obtain clock synchronization information from the grandmaster.

Context

A 1588v2 router runs the BMC algorithm to use the following parameters in sequence to select a master clock:

priority1
clock-class
clock-accuracy
priority2

For example, the router compares priority1 values of two candidates. If the two candidates have the same priority1 value, the router compares clock classes of the two candidates. The process repeats until the router selects a master clock.

Perform the following steps on each router that is connected to a BITS on a 1588v2 network:

Procedure

Run system-view
The system view is displayed.
Configure the type of the clock source to be traced.
This example uses the local clock and BITS1 signals. The actual number of BITS interfaces and their numbers depend on the hardware configuration.
```
ptp clock-source { local time-source time-source-value | bits1 time-source time-source-value }
```
This configuration can be performed only on the grandmaster clock. The time-source-value parameter is set based on the type of the clock source. For the mapping between the time-source-value parameter and clock source types, see ptp clock-source in the NetEngine 8000 F Command Reference.
Configure the accuracy of the clock source.
```
ptp clock-source { local clock-accuracy clock-accuracy-value | bits1 clock-accuracy clock-accuracy-value }
```
For the mapping between the clock-accuracy-value parameter and clock precision, see ptp clock-source in the NetEngine 8000 F Command Reference.
Configure the class of the clock source.
```
ptp clock-source { local clock-class clock-class-value | bits1 clock-accuracy clock-class-value }
```
For the mapping between the clock-class-value parameter and the clock source level, see ptp clock-source in the NetEngine 8000 F Command Reference.

If the clock-class-value value is less than 128, the device cannot function as a slave clock.
Configure priority1 of the clock source.
ptp clock-source { local priority1 priority1-value | bits1 priority1 priority1-value }
Configure priority2 of the clock source.
ptp clock-source { local priority2 priority2-value | bits1 priority2 priority2-value }
(Optional) Configure the grandmaster clock ID of the clock source.
ptp clock-source bits1 grandmaster-clockid grandmaster-clockid-value
(Optional) Configure the stability value of the clock source.
ptp clock-source bits1 offsetscaled-logvariance offsetscaled-logvariance-value
Run commit
The configuration is committed.