Editing Network planning and design (section)

==Dimensioning==
Dimensioning a new network determines the minimum capacity requirements that will still allow the [[Teletraffic Grade of Service]] (GoS) requirements to be met.<ref name="[1]"/><ref name="[*]" /> To do this, dimensioning involves planning for peak-hour traffic, i.e. that hour during the day during which traffic intensity is at its peak.<ref name="[1]"/>

The dimensioning process involves determining the network’s topology, routing plan, traffic [[matrix (mathematics)|matrix]], and GoS requirements, and using this information to determine the maximum call handling capacity of the [[network switch|switches]], and the maximum number of channels required between the switches.<ref name="[1]"/> This process requires a complex model that simulates the behavior of the network equipment and [[routing protocol]]s.

A dimensioning rule is that the planner must ensure that the traffic load should never approach a load of 100 percent.<ref name="[1]"/> To calculate the correct dimensioning to comply with the above rule, the planner must take on-going measurements of the network’s traffic, and continuously maintain and upgrade resources to meet the changing requirements.<ref name="[1]"/><ref name="[*]" /> Another reason for [[overprovisioning]] is to make sure that traffic can be rerouted in case a failure occurs in the network.

Because of its complexity, network dimensioning is typically done using specialized software tools. Whereas researchers typically develop custom software to study a particular problem, network operators typically make use of commercial network planning software.