Yealink SIP-T29G User Manual page 17

Line key LED (configured as a BLF key or BLF List key)
LED Status
Solid green
Fast flashing red (200ms)
Solid red
Slow flashing red (1s)
Off
Description
The monitored user is idle.
The monitored user receives an incoming call.
The monitored user is busy.
The monitored user's conversation is placed on
hold (This LED status requires server support).
The call is parked against the monitored user's
phone number.
The monitored user does not exist.
Overview
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