Measurement of traffic within a network allows network managers and analysts to both make day-to-day decisions about operations and to plan for long-term developments.
Traffic Measurements are conducted on a continuous basis and the results compiled into reports for management which are used in management decisions on various time scales.
[2] To determine normal reference traffic for a network, the ITU recommends that a network traffic analyst must take measurements for the busiest hour of each day for a whole year.
[2] To perform calculations in circuit-switched networks several assumptions are made:[3] It is useful to remember that the measurements are averages, and this process deliberately ignores very short term variations in the traffic, but still allows for a small but finite loss.
The above assumptions are accurate if applied to circuit switched networks; however they fail when planning for data traffic, small exchanges and sudden sharp peaks in traffic such as that caused by TV and radio phone-in competitions.