Setting Triggered Alarm Insertion

This topic describes how to implement the triggered alarm insertion to ensure that protection switching functions properly. In a network consisting of different IF cards that support different switching mechanisms for the SNCP ring, triggered alarm insertion is necessary.

Prerequisites

You are user with Operator Group authority or higher.

Context

The triggered alarm insertion is applicable only to an SNCP ring network with different IF cards. The insertion function is set on an appropriate IF card to ensure successful SNCP switching.

As shown in Figure 1, IF1 and IFU2 consist of a ring network. NE1 is the sink of the SNCP service, selectively receiving services from NE2 or NE5. When NE1 detects the TU_AIS alarm, protection switching is implemented. For example, the E1_AIS alarm is detected on IFU2 of NE2 if the microwave link between NE3 and NE4 is detected. When signals are transmitted to IF1 of NE2 by means of cross-connections, the signals are encapsulated with the correct TU overhead. As a result, the downstream NE1 cannot detect the TU_AIS alarm and no SNCP switching is triggered. The protection mechanism becomes invalid. In this case, insert the TU_AIS alarm for the E1_AIS alarm on IFU2 of NE2 to ensure successful SNCP switching at NE1.

Figure 1 SNCP protection in a ring network with IF1 and IFU2 cards

Procedure

In the NE Explorer, click the appropriate card and choose Alarm > Triggered Alarm Insertion from the Function Tree.
Select the required path, double-click the corresponding table cell in the Insert TU_AIS to E1_AIS column, and choose Enabled from the drop-down list.
Click Apply.