One way this requirement is addressed is through the use of different types of switches. Voice messages most often require a relatively small amount of bandwidth for a relatively long period of time. Usage is constant throughout that period, since even silence is significant and must be conveyed in real-time. The ideal environment for data transmission provides a large amount of bandwidth so each burst can get through quickly, but usage of this bandwidth is not constant. Variations in delay do not cause any problems for data connections, but they are much less tolerant of noise than are voice connections, so some error-correction measures are required.
Circuit switching is the method used in the voice network.
The function of circuit switching is to establish a dedicated communications path between customers. The voice telephone network is essentially a circuit-switched network. The resources thus assigned are used exclusively by the customer for the duration of the call. A call record for billing purposes is created during this phase. When the customer terminates the call the resources return to an idle state to make them available for new calls.