The geometric portrayal of computer & network device connection in a network is termed as the network topology. Topology determines in which direction & manner the exchange of information would take place. To design a network, it is vital to optimizing factors like speed, reliability, security, etc. Ring topology is a simplified topology which is widely used in network design.
What Is The Ring Topology?
The topology where network/communication devices are arranged, forming a complete closed path or a loop is called the ring topology. The closed way of this topology can be of a circular, triangular, quadrilateral, or any other shape.
In this topology, point to point connection is established between two devices. One computer or device is connected with two other devices on either side. Thus one single continuous communication route is created. Data travels from node to node; it goes through adjacent nodes one by one till it reaches the destination node.
Ring Topology Diagram
Figure: Unidirectional Ring Topology
In the unidirectional topology, data flows in one direction (either clockwise or anti-clockwise) through one single cable.
Figure: Bidirectional Ring Topology
In the Bidirectional topology, two cables carry data. Data flow in two opposite directions (one clock wise& the other one anti-clockwise) through two cables.
Ring Topology Classification
The topology is basically of two types depending on the data flow. They are unidirectional & bidirectional topology.
Nodes in this topology are connected with a single cable. Data flows in one single direction (clockwise/anti-clockwise). It’s an inexpensive topology to set up & maintain. In this type of topology, data is previously configured. Usually, the configuration is simplex. But in some cases, the topology can be configured as a half-duplex, where data can flow in both clockwise and anti-clockwise direction alternately through one cable but one direction at a time.
A pair of cables assembles all the network devices in this topology. Data flows in both direction i.e., clockwise & anti-clockwise. One node can easily communicate with two other nodes at the same moment. Bidirectional topology provides full-duplex transmission. Though it is a bit more expensive than the unidirectional one, it avails simultaneous communication with much reliability. In the event of failure of one cable, the other cable transmits data & keeps the communication going.
Collapsed ring topology is one special kind of the topology. To connect all nodes, a single cable is used, but end nodes are directly joined for redundancy purposes.
Ring topology characteristics:
Some essential features of ring topology are
- Each device on this topology includes a transmitter & a receiver; they play the role of the repeater.
- The transfer of data takes place sequentially. Data is transferred bit-wise i.e., bit by bit.
- The data is transferred through each node existing in the ring until it reaches the destination node.
- Multiple repeaters are used in the ring. Repeaters strengthen the data in the midway while traveling a long distance to reach the destination.
- Availability of inbuilt acknowledgment mechanism i.e., a token is passed on completion of the data/ message transmission from source to the destination node.
- The release of token nullifies the probability of collision or cross-communication in the ring.
- The charge of the network is on one device at a time; no two devices have permission to communicate at the same moment.
- Dual ring topology increases the network reliability as one link avails communication on inactivation of the other one.
Ring topology examples
SONET ring is one typical example of a ring topology. Synchronous Optical Networking (SONET) transfers heavyweight data in long distance. SONET uses a fiber optic cable. It is like the Fiber Optic Cable Ring Topology. This provides high reliability in a computer network for synchronization purposes, like synchronization of different branches of a company or a bank. For such synchronization, high data transfer speed is received.
SONET/SDH ring usually uses two sets of links that are bidirectional. The bidirectional link between two nodes allows the maintenance or disruption at multiple points of the same ring. It results in the preservation of primary traffic on the outer ring after the failure point by shifting the traffic on the inner one.
Ring Topology Advantages
Ring topology is quite beneficial to network users. Several benefits of using this topology are,
- Establishment & maintenance of the topology is quite easy.
- Multiple rings increase network reliability
- Peer to peer communication imparts genuine sharing of assets.
- Data flow pre-configuration
- Data transmission speed is notably high.
- No network overload occurs for adding new devices to the ring.
- Comparatively cheap topology.
- No requirement of additional devices in the form of hub & terminator saves the cost.
Ring Topology Disadvantages
Like the coin has two sides, the topology has some of the drawbacks too. Some disadvantages of ring topology are,
- Dysfunctioning of one node adversely affects the whole network.
- Diagnosing the error and troubleshooting is difficult.
- Simultaneous transmission among the existing network devices is not possible.
- Modification of the ring i.e., addition or removal of a device to the ring, is a bit difficult & tricky as well.
- There are chances the backbone cable to get damaged by the line drops & connectors.
- In comparison to star topology, it performs a bit slower.
- Data passes through adjacent nodes until it reaches the destination node. So this way of transmission is less secured, there are high chances an unauthorized person can access the data & sensitive information as well.
Where Ring Topology Is Used
There are multiple usages of the ring topology. It is found in the office building and school/college or university campus. Though it is an active topology, due to the widespread use of high-speed LAN, ring topology is less popular nowadays.
Token ring, Metro ring protocol, fiber distributed data interface are some of the standard protocols used in the ring topology. The network designer can choose one of the protocols as per the requirement.