1.2.9 Establish a Network Baseline
The purpose of network monitoring is to watch network performance in comparison to a predetermined baseline. A baseline is used to establish normal network or system performance to determine the “personality” of a network under normal conditions.
Establishing a network performance baseline requires collecting performance data from the ports and devices that are essential to network operation.
A network baseline should answer the following questions:
- How does the network perform during a normal or average day?
- Where are the most errors occurring?
- What part of the network is most heavily used?
- What part of the network is least used?
- Which devices should be monitored and what alert thresholds should be set?
- Can the network meet the identified policies?
Measuring the initial performance and availability of critical network devices and links allows a network administrator to determine the difference between abnormal behavior and proper network performance as the network grows or traffic patterns change. The baseline also provides insight into whether the current network design can meet business requirements. Without a baseline, no standard exists to measure the optimum nature of network traffic and congestion levels.
Analysis after an initial baseline also tends to reveal hidden problems. The collected data shows the true nature of congestion or potential congestion in a network. It may also reveal areas in the network that are underutilized, and quite often can lead to network redesign efforts, based on quality and capacity observations.
The initial network performance baseline sets the stage for measuring the effects of network changes and subsequent troubleshooting efforts. Therefore, it is important to plan for it carefully.