What is an important consideration when choosing a time period for collecting data to establish...

Establishing an accurate baseline is a cornerstone of theDesigning and Implementing Enterprise Network Assurance (300-445 ENNA)methodology. A baseline must represent the "typical" behavior of the network across its standard operating cycle to be useful for anomaly detection and capacity planning. When monitoring interface utilization on a critical link, it is vital tocapture both peak and off-peak traffic patterns(Option C).

Most enterprise networks exhibit cyclical traffic patterns, often referred to as "diurnal" cycles, where utilization spikes during business hours (peak) and drops significantly at night or on weekends (off-peak). If an engineer only collects data during the lowest volume period (Option A), the baseline will be unrealistically low, leading to "false positive" alerts when normal business traffic returns. Conversely, only capturing peak data might hide background synchronization tasks or backup windows that occur during off-hours.

By selecting a representative time period—typically one full week or a month—the engineer ensures the baseline accounts for variations such as Monday morning "logon storms," mid-week steady states, and weekend maintenance. This comprehensive view allows the assurance platform (such asCisco Catalyst CenterorThousandEyes) to calculate a standard deviation and establish dynamic thresholds. If utilization deviates from these historically representative norms, the system can trigger an alert based on a true anomaly rather than a predictable daily surge. Aligning with a financial year (Option B) is irrelevant to technical performance, and limiting the data (Option D) compromises the baseline's statistical validity.