Trunk Side Trunk is a communication line between two switching systems. A tie trunk connects PBXs. Central office trunks connect a PBX to the switching system at the central office. Tunneling A way of overcoming protocol restrictions on a network by encapsulating packets that use one protocol inside packets that use a protocol supported by the network. The wires are twisted around each other to minimize interference from other twisted pairs in the cable.
Twisted pair is common in telephone wiring and is increasingly common in data networks.
Other high-speed forms of cable include coaxial and fiber optic cables. Cable A cable consisting of four or more copper wires twisted together in pairs. Telephone wiring is an example of twisted-pair cable. Twisted-pair cable can be shielded or unshielded.