A ring network is a network topology in which each node connects exactly to two other nodes, forming a single continuous path for signals through each node – a ring. Data is transferred from one node to another, with each node processing each packet along the way. Rings can be used to carry circuits or packages or a combination of both. SDH rings carry circuits. Circuits are configured using out-of-band signaling protocols, while packets are typically transmitted via a Medium Access Control Protocol (MAC). In a ring network, data packets travel from one device to another until they reach their destination. Most ring topologies allow packets to move in a single direction, called a unidirectional ring network. Others allow data to move in both directions, which is called bidirectional. The purpose of media access control is to determine which station is sending and when. As with any MAC protocol, the goal is to resolve disputes and ensure fairness. There are three main classes of media access protocol for ring networks: slotted, token, and register insertion.
The main disadvantage of a ring topology is that a single connection in the ring affects the entire network. A ring topology is a network configuration in which device connections create a circular data path. Each networked device is connected to two others, for example, .B. with dots on a circle. Together, the devices in a ring topology are called ring networks. Rings can be unidirectional, with all traffic flowing around the ring clockwise or counterclockwise, or bidirectional (as in SONET/SDH). Because a one-way ring topology provides only one path between two nodes, unidirectional ring networks can be interrupted by the failure of a single connection.  A node failure or cable break can isolate any node connected to the ring. In response, some ring networks add a “counter-rotating ring” (C ring) to form a redundant topology: in the event of an interruption, data is returned to the complementary ring before reaching the end of the cable, maintaining a path to each node along the resulting C ring.
These “dual ring” networks include the Network Signalling System No PSTN telephony systems. 7 (SS7), spatial reuse protocol, Fiber Distributed Data Interface (FDDI) and Resilient Packet Ring. IEEE 802.5 networks – also known as IBM Token Ring networks – completely avoid the weakness of a ring topology: they actually use a star topology on the physical layer and a media access unit (MAU) to mimic a ring on the data link layer. The entire Signaling System No. 7 (SS7) and some SONET/SDH rings have two sets of bidirectional connections between the nodes. This allows maintenance or failures at multiple points in the ring, usually without loss of primary traffic on the outer ring, by switching traffic beyond the point of failure to the inner ring. The split ring treats the latency of the ring network as a large lag register that rotates continuously. It is formatted in so-called fixed-size locations. A location is full or empty, as indicated by the control indicators in the location header. A station that wants to send waits for an empty location and enters data. Other stations can copy the data and release the location, or it can return to the source that releases it. One of the advantages of the source version, when the sender is excluded from immediate reuse, is that all other broadcasters have the option to use it first, thus avoiding bandwidth depletion.
The outstanding example of the split ring is the Cambridge Ring. In the past, ring topology was most often used in schools, offices, and small buildings where networks were smaller. Today, however, the ring topology is rarely used because it has been moved to another type of network topology to improve performance, stability, or support. Ring topologies can be used in local area networks (LANs) or wide area networks (WANs). Depending on the network adapter used in each ring topology computer, a coaxial cable or an RJ-45 network cable is used to connect the computers to each other. .