It is quite usual that disturbances happen in any Local Area Network (LAN), Metropolitan Area Network (MAN), Wide Area Network (WAN) or even wireless networks. The vitality of network monitoring is derived from the need for continuous availability of network services, servers and other devices - not to mention the enhanced security and management advantages as well.

Once an abnormal behavior or action is noted, a server becomes down or a service becomes unavailable, a good network monitoring software will attempt to reinstate the activity, server or service into its previous "normal" or "available" state.

The best network monitoring software applications have built in resolution scenario cases to be conducted according to whichever action or service becomes unavailable. Even after these resolution attempts, there is a need to establish an alerting system to signal the network administrator or group of officials with the situation at hand.

Having established the need to an alerting system, we can then move onto discussing the various alerting methods. Most network monitoring software generally used all or a combination of the following alerting methods:

• Short Messaging Service (SMS)
• ICQ Messages
• Microsoft MSN Messenger messages
• AIM Messages
• Primary and Secondary SMTP (Simple Mail Transfer Protocol) which sends an email to the specified person or persons (within a queue or list of prerogative actions).
• Pager Messages
• Recorded voice message calls to specified cellular phone numbers (usually of responsible personnel)

Suppose your company has a team responsible for the network, its activity and operation monitoring. In case anything wrong or abnormal goes on, the monitoring software triggers the alerting subsystem. If for instance there are 4 members of this team, then different alert types may be assigned to each individual member as well as different hierarchies of alerts.

Consider the team of Sara, Rob, Mark and Alice. Most software monitoring products allow for the following simple example schedule and settings to be configured:
(TEAM A)

With the recurrence of the problem, or the increase of the duration of time before a counter action is undertaken, a secondary SMTP message could be sent to Rob.

There are many scenarios that could be established in order to reduce the risk of irreversible damage to the network or to the business activity as a result of a network failure. In fact, it is important to design water-proof scenarios (so to speak), so as to minimize or even nullify the percentage of risk of not having anyone there to solve/ monitor the problem.

Another issue is that of the on call option. Consider an alert triggered on a Friday at about 10 a.m. If Mark was absent that day, and his status is configured as NOT on call, then the next person on the list to alert would be Alice. A primary SMS message will therefore be sent to Alice.

Moreover, several teams may be defined with different activity statuses during different times of the year or month. Team A above may be active during the fall months (September through February), while another Team B may be inactive then and active from March through August.

If a new member, Jim joins Team A with Sara's schedule, then all Team A's alerts apply to him automatically (those of Sara's). The same goes if a team member leaves the company, or edits anything in his/her profile; no changes in the alert settings are necessary. This indeed is an added advantage of configuring Persons and Teams in the network monitoring software you're using.