Architecture

In a ring topology, each device connects to exactly two neighboring devices, forming a closed loop:

        A --- B
       /       \
      E         C
       \       /
        D-----'

Working

• Data travels around the ring in one direction (unidirectional) or both (bidirectional/dual-ring).
• Each node acts as a repeater: it receives a frame, checks the destination address, and either passes it along unchanged (if not the destination) or copies it (if it is the destination) before also forwarding it onward to remove it from the ring.
• Access to the ring is commonly controlled with a token (Token Ring): a special frame circulates; a node may transmit only when it holds the token, preventing collisions.

Advantages

• No collisions — orderly, predictable access via token passing.
• Equal access opportunity for all nodes (fair, no central bottleneck).
• Relatively simple to install and reconfigure by adding nodes at any point in the loop.
• Performance degrades more gracefully under heavy load than contention-based systems (like plain Ethernet/CSMA).

Disadvantages

• A single link or node failure can break the entire ring (in a simple, non-redundant ring), disrupting the whole network — mitigated by dual-ring designs.
• Adding or removing a node typically requires briefly bringing the ring down.
• Total network delay increases with the number of nodes, since each node adds processing/repeat delay.
• Troubleshooting can be harder than in a star topology, since there's no central point to monitor from.