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Use the Maintenance option to schedule maintenance events for nodes and links. Maintenance events are planned failures of network elements at specific future dates and times. During a scheduled maintenance event, the selected elements are considered logically down, and the system reroutes the LSPs around those elements during the maintenance period. After the maintenance event is completed, delegated and PCE-initiated LSPs are reverted back to optimal paths.

Add a new maintenance event by clicking the Maintenance tab in the Network Information table, and clicking Add at the bottom of the table. The Add Maintenance Event window is displayed as shown in Figure 1.

Figure 1: Add Maintenance Event Window, Properties Tab
Add Maintenance Event Window,
Properties Tab

Table 1 describes the data entry fields available in the Properties tab.

Table 1: Add Maintenance Event Window, Properties Fields




Enter a name for the maintenance event.


This field auto-populates with the user that is scheduling the maintenance event.


Enter a comment for the maintenance event.


Click the calendar icon to display a monthly calender from which you can select the year, month, day, and time.


Click the calendar icon to display a monthly calender from which you can select the year, month, day, and time.

Auto Complete at End Time

Select the Auto Complete at End Time check box to automatically complete the maintenance event (bring the elements back up) at the specified end time. If the check box is not selected, you must manually complete the maintenance event after it finishes.

When a maintenance event is completed, it means that the maintenance event window has ended and all elements are logically brought to an Up state, ready for path recalculation. LSPs are then rerouted to optimal paths.

Note: To manually complete an event, select it in the Network Information pane of the Topology view, click Modify, and use the drop-down menu in the Status field to select Completed.

Use the Nodes, Links, and SRLG tabs to select the elements that are to be included in the maintenance event. All three of these tabs are structured in the same way. Figure 2 shows an example.

Figure 2: Select Elements for Maintenance Event
Select Elements for
Maintenance Event

Select elements in the Available column and click the right arrow to move them to the Selected column. Click the left arrow to deselect elements. Click Submit when finished. The new maintenance event appears in the Network Information table at the bottom of the Topology view.

When an element (node, link, or SRLG) is undergoing a maintenance event, it appears on the topology map with an M (for maintenance) through the element. Figure 3 shows an example.

Figure 3: Node Undergoing Maintenance
Node Undergoing Maintenance

You can evaluate the effects of a maintenance event using the Simulate Maintenance Event function. To access this function, right-click in the maintenance event row in the Network Information table and select Simulate.

The Maintenance Event Simulation window, as shown in Figure 4, displays the nodes, links, and SRLGs you selected to include in the event.

Figure 4: Maintenance Event Simulation Window
Maintenance Event Simulation

The Exhaustive Failure Simulation section at the bottom of the window is optional. It provides check boxes for selecting the element types you want to include in an exhaustive failure simulation. If you do not perform an exhaustive failure simulation (all check boxes under Exhaustive Failure Simulation are cleared), all the nodes, links, and SRLGs selected for the maintenance event fail concurrently. In Figure 4, for example, node 0110.0000.0199, link L11.106.107.1_11.106.107.2, and SRLG 100 would all fail at the same time.

Using this same example, but with Nodes selected under Exhaustive Failure Simulation, the simulation still fails all the maintenance event elements concurrently, but simultaneously fails each of the other nodes in the topology, one at a time. If you select multiple element types for exhaustive failure simulation, all possible combinations involving those elements are tested. The subsequent report reflects peak values based on the worst performing combination.

Whether or not you select exhaustive failure, click Simulate to perform the simulation and generate a report. You can view the report using the Applications menu by navigating to Applications>Reports.