A System of Local Area networking in which each Node or station is connected to two others, ultimately forming a loop. Data are passed in one direction only, being received by each node and then transferred to the next node. Access is achieved either by means of a token, passed from one node to the other, or by polling, a kind of inquiry made by a master station. Also known as a ring network.

A double ring that consists of two independent rings, a Primary and a secondary, with traffic flowing in opposite directions. A computer that is connected to both rings is called a Dual Attachment Station (DAS), and when one of the rings is broken by a Cable fault, the computer switches to the other ring, providing continued full access to the entire network. The double ring is suited to use as a Backbone network.