A signalling event occurs when a transmitter alters the physical state of a channel, such as shifting a voltage level, changing a phase, or modifying a frequency, to represent a piece of data. The rate of these events is measured in baud. In telecommunications, tracking signalling events helps diagnose protocol failures during call setup or data handshakes.
Heard on the job
The trace shows a signalling event for the line seizure, but we never receive the digits from the PBX.
Related terms
Baud
A measure of signaling rate representing the number of state changes per second on a communications channel.
Symbol
The smallest distinct change in a transmission signal that carries data.
In-band signaling
The transmission of network control signals over the same channel used for the actual voice or data payload.