Chapter 7: Does Your SNMP Manager Support These 7 Key Telemetry Functions?

SNMP is a standard protocol that has wide acceptance in the industry and is flexible enough to describe almost anything. (See the SNMP Tutorial for more information.) Because of these advantages, many network managers have come to believe that SNMP should be used for all telemetry monitoring applications.

SNMP certainly has its place in an effective telemetry monitoring solution, but this doesn't mean that any off-the-shelf SNMP manager can provide adequate visibility and control of your network.

The typical off-the-shelf SNMP manager is not designed for displaying and processing telemetry data for effective alarm management, especially for the kind of real-world monitoring tasks network managers most need performed. These capabilities can be added to an SNMP manager, but it usually requires substantial custom software development.

Before you buy, make sure your SNMP manager supports these 7 key functions

Here's a list of seven key telemetry functions that off-the-shelf SNMP managers typically do not support. These are essential functions that you need for best-quality monitoring of your network. Before you buy an SNMP manager, make sure it supports these seven essential functions.

1. Complete, precise alarm descriptions
   A basic SNMP manager doesn't record the location, time, severity, or a precise description of alarm events. To adapt an off-the-shelf SNMP manager to monitor these factors, you must create and maintain a master alarm list representing all the monitored points in your network - and then also create and maintain a database associating all the traps that may be sent to the SNMP manager with the alarms on that list. (Traps are a type of SNMP message sent from an SNMP agent, such as an RTU - see our SNMP Tutorial Series to learn more about SNMP.)
2. Identification of cleared alarms
   Even more database work is required to identify whether a trap corresponds to an alarm condition or a clear condition. Creating this addition to the trap association database often requires analyzing multiple variable bindings within the trap packet.
3. Standing alarm list
   Relying on a basic SNMP manager for alarm management can potentially result in completely losing visibility of threats to your network. A basic SNMP manager doesn't maintain a list of standing alarms. Instead, the typical SNMP manager maintains an event log of newly reported traps and a history log of acknowledged traps. As soon as a trap is acknowledged, it is considered cleared. Imagine what might happen to your network if a system operator acknowledges an alarm, and then, for whatever reason, fails to correct the alarm condition. Who would know the alarm is still standing?