Shared line appearance (SLA) mimics the traditional KSU (key system unit) interface where all PSTN lines are shown on each phone, allowing users to hold and answer calls from any phone.
Shared Line Appearance is when one button on multiple phones can be set up to share the same line. The line should have an LED associated with the button to indicate the status of the corresponding line. Upon an inbound call to the "Shared Line", all the available phones associated with the "Shared Line" will be rung, and the LED for the associated button should be flashing. The call can be answered at any of the associated phones simply by pressing the button associated with that line.
Once the call is answered, the LED for the associated button will stay on continuously. Calls can be parked by pressing the button for that line and then retrieved by pressing the "shared line" button on any of the other associated phones. When the call ends, the LED associated with the line goes off on all of the phones. Outbound calls can be made by pressing the button to select one of the available "Shared Lines" (indicated by their associated LED turned off), then dial the number you wish to dial.
SLA is supported for a maximum of 6 lines on each device.