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Measuring Availability

There are two methods you can use to measure availability:

Proactive—Availability is automatically measured as often as possible by an operational support system.
Reactive—Availability is recorded by a Help desk when a fault is first reported by a user or a fault monitoring system.

This section discusses real-time performance monitoring as a proactive monitoring solution.

Real-Time Performance Monitoring

Juniper Networks provides a real-time performance monitoring (RPM) service to monitor real-time network performance. Use the J-Web Quick Configuration feature to configure real-time performance monitoring parameters used in real-time performance monitoring tests. (J-Web Quick Configuration is a browser-based GUI that runs on Juniper Networks routers. For more information, see the J-Web Interface User Guide.)

Configuring Real-Time Performance Monitoring

Some of the most common options you can configure for real-time performance monitoring tests are shown in Table 27.

Table 27: Real-Time Performance Monitoring Configuration Options

Field	Description
Request Information
Probe Type	Type of probe to send as part of the test. Probe types can be: http-get http-get-metadata icmp-ping icmp-ping-timestamp tcp-ping udp-ping
Interval	Wait time (in seconds) between each probe transmission. The range is 1 to 255 seconds.
Test Interval	Wait time (in seconds) between tests. The range is 0 to 86400 seconds.
Probe Count	Total number of probes sent for each test. The range is 1 to 15 probes.
Destination Port	TCP or UDP port to which probes are sent. Use number 7—a standard TCP or UDP port number—or select a port number from 49152 through 65535.
DSCP Bits	Differentiated Services code point (DSCP) bits. This value must be a valid 6-bit pattern. The default is 000000.
Data Size	Size (in bytes) of the data portion of the ICMP probes. The range is 0 to 65507 bytes.
Data Fill	Contents of the data portion of the ICMP probes. Contents must be a hexadecimal value. The range is 1 to 800h.
Maximum Probe Thresholds
Successive Lost Probes	Total number of probes that must be lost successively to trigger a probe failure and generate a system log message. The range is 0 to 15 probes.
Lost Probes	Total number of probes that must be lost to trigger a probe failure and generate a system log message. The range is 0 to 15 probes.
Round Trip Time	Total round-trip time (in microseconds) from the Services Router to the remote server, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Jitter	Total jitter (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Standard Deviation	Maximum allowable standard deviation (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Egress Time	Total one-way time (in microseconds) from the router to the remote server, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Ingress Time	Total one-way time (in microseconds) from the remote server to the router, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Jitter Engress Time	Total outbound-time jitter (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Jitter Ingress Time	Total inbound-time jitter (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Egress Standard Deviation	Maximum allowable standard deviation of outbound times (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.
Ingress Standard Deviation	Maximum allowable standard deviation of inbound times (in microseconds) for a test, which, if exceeded, triggers a probe failure and generates a system log message. The range is 0 to 60,000,000 microseconds.

Displaying Real-Time Performance Monitoring Information

For each real-time performance monitoring test configured on the routing platform, monitoring information includes the round-trip time, jitter, and standard deviation. To view this information, select Monitor > RPM in the J-Web interface, or enter the show services rpm CLI command.

To display the results of the most recent real-time performance monitoring probes, enter the show services rpm probe-results CLI command:

user@host> show services rpm probe-results

Owner: p1, Test: t1
   Target address: 10.8.4.1, Source address: 10.8.4.2, Probe type: icmp-ping
   Destination interface name: lt-0/0/0.0
   Test size: 10 probes
   Probe results:
      Response received, Sun Jul 10 19:07:34 2005
      Rtt: 50302 usec
   Results over current test:
      Probes sent: 2, Probes received: 1, Loss percentage: 50
      Measurement: Round trip time
        Minimum: 50302 usec, Maximum: 50302 usec, Average: 50302 usec,
        Jitter: 0 usec, Stddev: 0 usec
   Results over all tests:
      Probes sent: 2, Probes received: 1, Loss percentage: 50
      Measurement: Round trip time
        Minimum: 50302 usec, Maximum: 50302 usec, Average: 50302 usec,
        Jitter: 0 usec, Stddev: 0 usec

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