Helps you properly configure the clock

Configuring the NE Clock Source

Before configuring services, you must configure the NE clock source and specify the priority level to ensure that correct clock tracing relationships are created for all the NEs in the network.

Prerequisites

You must be an NM user with NE operator authority or higher.

Background Information

To implement clock protection, you must configure at least two traceable clock sources for the equipment. Usually, the tributary clock is not used as the clock source for the equipment.

After you set the clock sources for all the NEs, query the networkwide clock tracing status again.

Procedure

1.     In the NE Explorer, select an NE and choose Configuration > Clock > Physical Layer Clock > Clock Source Priority from the Function Tree.

2.     Click Query to query the existing clock source.

3.     Click Create. In the Add Clock Source dialog box, select a new clock source and click OK.

4.     Optional: If an external clock source is selected, select External Clock Source Mode based on the type of external clock signals. In the case 2 Mbit/s clocks, specifySynchronous Status Byte to deliver SSM messages.

5.     Select a clock source, and click  or  to adjust its priority level. The clock sources are arranged in descending order. The clock source on top is preferred for the NE.

NOTE:

Internal clock sources have the lowest priority because of their low precision.

6.     Click Apply. In the Operation Result dialog box, click Close.

NOTE:

If the clock tracing relationship changes because of change in the clock source, the Prompt dialog box is displayed, asking you whether to refresh the clock tracing relationship. ClickOK. If you select Disable Prompting Next Time, no prompt is displayed even when the clock tracing relationship changes.

7.     Optional: If you select the line clock as the phase-locked source, you need to specify the priority table for the phase-locked sources. Click the Priority Table for Phase-Locked Sources of 1st External Clock Output tab, and then click Create. In the dialog box that is displayed, select the phase-locked source, and click OK.

8.     Click Apply. In the dialog box that is displayed, click Close.

Configuring the Clock Source Protection

On a complicated clock network, you need to configure the clock protection for all NEs. After you set the clock source and specify the clock priority level for the NEs, you can enable the standard SSM or extended SSM protocol to prevent the NEs from tracing an incorrect clock source. This is how the clocks are protected.

Prerequisites

You must be an NM user with NE operator authority or higher.

Procedure

1.     In the NE Explorer, select an NE and choose Configuration > Clock > Physical Layer Clock > Clock Subnet Configuration from the Function Tree.

2.     Click the Clock Subnet tab. Click Query to query the existing parameter settings.

3.     Select Start Standard SSM Protocol or Start Extended SSM Protocol.

NOTE:

The same SSM protection protocol must be used for the same clock protection subnet.

4.     Set the subnet number of the clock subnet that the NE belongs to.

NOTE:

Allocate the same subnet number to NEs tracing the same clock source.

5.     Optional: If the extended SSM protocol is enabled, set the clock ID of the clock source.

6.     Click Apply. In the Operation Result dialog box, click Close.

7.     Optional: If the clock ID is specified for the line clock of an NE, click the Clock ID Status tab, and set the Enabled Status to Enabled. Click Apply. In the Operation Result dialog box, click Close.