You can administer the system to route calls to the attendant when the called user hangs up, but the caller does not. The attendant can then use Attendant Serial Calling to transfer the call to another user, at the request of the caller. The attendant can transfer calls only to those users on the same server.

This feature helps the attendant to use the trunks efficiently. If few trunks are available, and direct inward dialing (DID) is unavailable, a caller might make several attempts to complete a call before the caller is successful. When a caller makes a successful call to the attendant, the user can use the same line into the server for multiple telephone calls.

The attendant display shows the attendant that an incoming call is a serial call.