Node (computer networking)

In networking, a node (Latin: nodus, 'knot') is either a redistribution point or a communication endpoint within telecommunication networks or computer networks.

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 communication channel. In data communication, a physical network node may either be data communication equipment (such as a modem, hub, bridge or switch) or data terminal equipment (such as a digital telephone handset, a printer or a host computer).

A passive distribution point, such as a distribution frame or patch panel is not considered to be a node.

Computer networks

In data communication, a physical network node may either be data communication equipment (DCE) such as a modem, hub, bridge or switch; or data terminal equipment (DTE) such as a digital telephone handset, a printer or a host computer.

If a network is a local area network (LAN) or wide area network (WAN), every LAN or WAN node that participates on the data link layer must have a network address, typically one for each network interface controller it possesses. Examples are computers, a DSL modem with Ethernet interface and wireless access point. Equipment, such as an Ethernet hub or modem with serial interface, that operates only below the data link layer does not require a network address.

If the network in question is the Internet or an intranet, many physical network nodes are host computers, also known as Internet nodes, identified by an IP address, and all hosts are physical network nodes. However, some data-link-layer devices such as switches, bridges and wireless access points do not have an IP host address (except sometimes for administrative purposes), and are not considered to be Internet nodes or hosts, but are considered physical network nodes and LAN nodes.