IP Phone User Manual

1.10 Conversation Features
Feature Guide 129
1.10.10 Calling Party Control (CPC) Signal Detection
Description
The Calling Party Control (CPC) signal is an on-hook indication (disconnect signal) sent from
the analogue trunk when the other party is hung up. To maintain efficient utilisation of trunks,
the PBX monitors their state and when CPC signal is detected from a line, the PBX disconnects
the line and alerts the extension with reorder tone.
Conditions
• CPC signal detection is programmable for incoming trunk calls ( LCOT CPC Signal
Detection Time—Incoming [414]), and for outgoing trunk calls ( LCOT CPC Signal
Detection Time—Outgoing [413]).
• If your telephone company sends signals similar to CPC, it is recommended not to enable
CPC signal detection on outgoing trunk calls.
• If CPC signal is detected during a Conference call ( 1.13.1.2 Conference), the line is
disconnected. The remaining parties stay connected.
• If CPC signal is detected during a call between a caller using the DISA feature ( 1.16.6
Direct Inward System Access (DISA)) and an extension or an outside party, the line is
disconnected.