A shared communications channel between two points. Coined by the telephone industry, a trunk typically refers to a high-bandwidth, fiber-optic line between switching centers (central offices). Telephone trunks handle thousands of simultaneous voice and data signals, whereas telephone "lines" are the wires from the central office to the customer.
The term migrated to the information networking industry and may refer to a high-speed or medium-speed channel for data packets.
SIP Trunks
With the advent of voice over IP (VoIP), a SIP trunk is assigned by a SIP provider to a customer, and a single trunk supports one or more telephone numbers (see
SIP trunking). See
central office.