Panasonic KX-TVM50 Installation Manual page 124

5.1.3 PBX Requirements for Inband Integration
Follow-on ID or Called Party ID
When forwarding or transferring a call to the VPS, a PBX with Follow-on ID sends the mailbox number of the
called subscriber to the VPS before connecting the caller. The VPS responds by playing that subscriber's
personal greeting. This operation is sometimes called Call Forward to Mailbox. Without this feature, the VPS
cannot immediately play the called extension's greeting message when the line is busy or there is no answer
because the VPS does not know which mailbox to send the caller to.
124 Installation Manual Document Version 2.1 2008/04