Nearest active upstream neighbor

Meaning – The term nearest active upstream neighbor, refers to the station sending data directly to a given station on the ring. In a token ring network, the station precedes this station. When the network beacons, the NAUN initiates the beacon removal process.

A token-ring network is a local area network (LAN) topology that sends data in one direction throughout a specified number of locations by using a token.

The token is the symbol of authority for control of the transmission line. This token allows any sending station in the network (ring) to send data when the token arrives at that location.

Example of usage“Stations in a token-ring network are physically connected, typically in a star-wired ring topology, to a wiring concentrator such as the IBM 8228 Multistation Access Unit. The concentrator serves as a logical ring around which data is transmitted at 4 million, 16 million, or 100 million bits per second (Mbps).”