Beaconing is a technique used on token-passing networks for monitoring the status of the token-passing process.
What is Beaconing?
Beaconing is a technique used on token-passing networks for monitoring the status of the token-passing process. Beaconing is used in token ring and Fiber Distributed Data Interface (FDDI) networks to ensure that token passing is functioning properly.
How does Beaconing work?
On a token-passing network such as FDDI, every station is responsible for monitoring the status of the token-passing process.
If a station detects that a fault has occurred, it starts placing beacons onto the ring. When the next station on the ring detects a beacon, it in turn starts placing beacons on the ring, and the first station stops transmitting them.

This process will continue until the station immediately upstream of the fault location is the only station sending beacons. This allows administrators to quickly locate the fault and repair it.
Once the fault is fixed, the station emitting the beacon detects its own beacon returning to it after traveling around the ring, and the station stops beaconing.