Sidebar: Terminology

ATM -- Asynchronous Transfer Mode, a digital communications technology that uses 53-byte packets of data (cells) for LANs, MANs, and WANs, and is commonly associated with high-speed networks. ATM can support applications that include computer networks, voice, and video.

OC3 -- Optical Carrier 3, a physical circuit specification that transfers data at about 155 megabits per second (Mbps) over fiber optic cabling.

OC12 -- Optical Carrier 12, 622 Mbps.

OC48 -- Optical Carrier 48, 2.4 gigabits per second (Gbps).

DS3 -- Digital Signal level 3, a physical circuit specification that trasfers data at about 45 Mbps over metallic cabling, also known as T3.

SONET -- Synchronous Optical Network.

VC -- Virtual Circuit, a term used in ATM (and other networking technologies) to describe a number of physical circuits, connected by switches, that are configured to pass data (cells) between two specific points on the network.

VP -- Virtual Path, a term used to describe a number of physical circuits, connected by switches, that are configured to pass virtual circuits between two specific points on the network.

VCI -- Virtual Circuit Indicator, a number used to reference a specific virtual circuit.

VPI -- Virtual Path Indicator, a number used to reference a specific virtual path.