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In telecommunications networks, a node (Latin nodus, 'knot') is either a redistribution point or a communication endpoint. The definition of a node depends on the network and protocol layer referred to. A physical network node is an electronic device that is attached to a network, and is capable of creating, receiving, or transmitting information over a communications channel. A passive distribution point such as a distribution frame or patch panel is consequently not a node.

A physical link is a dedicated connection for communication that uses some physical media (electrical, electromagnetic, optical, to include clear spaces or vacuums.) A physical link represents only a single hop (link) in any larger communcations path, circuit, or network. NOTE: not synonymous with data link as a data link can be over a telecommunications circuit, which may be a virtual circuit composed of multiple phyical links.