A busy lamp field lets you monitor and answer a colleague's extension. If you speak with that person frequently, you can easily dial the number by pressing the busy lamp field key, indicated with a silhouette icon. In addition, busy lamp fields can be used while transferring calls to your colleague's line and adding people to a conference call.
Your phone will have one or two private lines and are identified with your extension and a handset icon. Lines programmed as busy lamp fields fall below your private lines and are identified by a silhouette icon (gray on a VVX 3xx phone and blue on a VVX 4xx phone).
Busy lamp fields have similar, but more powerful functionality, than shared call appearances. When you answer a busy lamp field, you are pulling the call from the busy lamp field to your primary line. It cannot be placed on hold and resumed on the owner's phone. If the owner needs to resume the call, you must transfer the call back to the owner.
To answer an incoming call for a busy lamp field:
In addition to answering and monitoring other’s lines, use busy lamp field keys as short cuts, so you don't have to manually dial extensions for these actions: