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 used in many fundamental activities such as:
- Calls arrivals follow a Poisson distribution
- Holding times follow a Negative Exponential distribution
- Blocked calls are lost or overflow
- There is statistical equilibrium
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.
Traffic measurement errors
Measurement errors are caused by faults in equipment or constraints on equipment design. The following five errors are examples of some types of errors that can occur: