I Figure 6-4: Circuit Switching The Pstn has traditionally used circuit sw itching a circuit is an end-to-end connection between two subscribers Capacity is reserved on all trunk lines and sw itches along the w ay 日日 Capacity must be paid for even if it is not used 6-116-11 Figure 6-4: Circuit Switching A circuit is an end-to-end connection betw een tw o subscribers. Capacity is reserved on all trunk lines and sw itches along the w ay. Capacity must be paid for even if it is not used. The PSTN has traditionally used circuit sw itching