Sample STM threshold-crossing alarm configuration

Threshold-crossing alarm configuration scenario

The following sample configuration focuses on the configuration of a threshold-crossing alarm that is to be included in a test suite. It does not describe the configuration of the test suite, schedule or scheduled task associated with the sample. No test policy is required for the configuration, as it does not involve generated tests.

A network provider needs to use the NFM-P to monitor a customer VPLS named VPLS 17 that carries VoIP traffic. The goal is to have the NFM-P raise an alarm when the round-trip jitter value rises above a specified threshold.

Network jitter values typically range from 10 to 15 ms, but are occasionally as high as 25 ms. Jitter buffers in the end-user VoIP sets can accommodate up to 80 ms of jitter. A network engineer determines that a jitter test threshold of 30 ms is low enough to allow NOC operators sufficient time for investigating a jitter increase, yet high enough to exclude spurious jitter events.

An NFM-P administrator wants to create a scheduled CPE ping test suite for the VPLS that periodically measures the round-trip jitter between each VPLS site and an end device. The administrator creates one CPE ping test for each site in the VPLS.

Sample threshold-crossing alarm configuration steps

The following procedure defines the configuration steps required for this sample. See Sample STM network SLA monitoring configuration for information about sample test suite, test policy, or scheduling configurations. See the procedures in Procedures to use the STM for complete STM configuration information. For conciseness, the procedure lists only the configuration steps that are specific to and necessary for the sample.

Create CPE ping test with threshold-crossing criteria

Click Create on the Service Test Manager (STM) form and choose L2 Service→CPE Ping. The CPE Ping (Create) form opens.

Configure the parameters in Table 89-11, General CPE Ping test parameters using the supplied values.

Table 89-11: General CPE Ping test parameters

Parameter	Value	Comment
General tab
Name	CPE Ping Test - VPLS 17, Site A	A descriptive name such as this is helpful for quickly identifying the entity under test when viewing the test results.
NE Schedulable	enabled	You must enable this parameter to allow the configuration of threshold-crossing criteria.
Select (in the Service panel)	VPLS 17	Click Search on the Select Service - CPE Ping form, then choose a service.
Select (in the Site panel)	Site A	Click Search on the Select Site - CPE Ping form, then choose a service.
Destination Path Address	IP address of an end device connected to Site A	Defines the IP address to which the CPE ping packets are sent.
Source IP Address	IP address of the NE that originates the test packets	This IP address must be in the same subnet as the Destination IP Address.
Source MAC Address	MAC address of the NE that originates the test packets	—
Test parameters tab
Number of Test Probes	5	A value of 5 provides more analysis granularity than a single test probe, without affecting network performance.
Results configuration tab
Probe History Size (rows)	100	This value provides a greater retained test-result history for occasional monitoring by an NFM-P operator.
Trap Generation	Probe Failure	Test-probe failures provide early notification of congestion or reachability issues to an NFM-P operator for troubleshooting purposes.

Click Apply. Additional buttons and tabs are displayed, and the form name changes to CPE Ping Test Name (Edit).

Click on the Threshold Alarms tab.

Click Add to add threshold criteria. The NE Threshold Event (Create) form opens.

Configure the parameters in Table 89-12, Threshold-crossing CPE Ping test parameters using the supplied values.

Table 89-12: Threshold-crossing CPE Ping test parameters

Parameter	Value	Comment
Type	Round-Trip Jitter	—
Generate Alarm on Rising Threshold	enabled	This is the default setting. Alternatively or additionally, by enabling the Generate Alarm on Rising Threshold parameter, you can configure the NFM-P to generate an alarm when a test-result value falls below a specified threshold. You can also configure the NFM-P to clear a rising-threshold alarm when the test-result value falls below the value configured for the falling threshold.
Rising Threshold tab
Threshold Value	30	This value specifies that the NFM-P is to generate an alarm when an individual test result contains a round-trip jitter value greater than 30 ms.

Save your changes and close the forms.