User`s guide

476 5967–9446

Historical Statistics

NetMetrix Historical Statistics application lets you view past network

activity and develop baselines that help you discern patterns of activity,

trends in behavior, and exceptional events.

By looking at short-term statistics, you can identify network perfor-

mance problems; long-term statistics assist you in network

conﬁguration, capacity planning, and network segmentation.

Three studies can be viewed: hourly, which shows data at 5-second inter-

vals; daily, at 30-second intervals; and monthly, at 30-minute intervals.

You can also choose to have historical data collected in data ﬁles on your

management station, allowing you to view long-term trends and calcu-

late baselines.

Baselines combine historical measurements with statistical algorithms

to analyze network data. In particular, baselines:

● Highlight exceptional activity, helping to pinpoint network problems.

● Show network patterns, helping you discover what’s normal for your

site. This information is useful when setting alarms that trigger when

something is abnormal.

● Reveal long-term trends, which is useful when planning expansions

and purchasing equipment based on utilization growth.

For a list of what agents work with Historical Statistics, refer to table 1

on page 18.

Multiple Interfaces

You cannot view Historical Statistics for data sources using a network

interface other than 1 (that is, for a non-default interface) from

OpenView NNM, unless the agent is a multi-interface HP LanProbe or a

Cisco switch. If you select other multi-interface agents in the OpenView

NNM map, any statistics graph that you view will be for the default

interface (on all selected items). To view statistics for non-default

interfaces on these agents, use Agent Manager.