1.3 CFeature Manual 63r) → 1.20.4 Wireless XDP Parallel Modes) → 1.16.1 SMDR (Station Message Detail Recording)—SMDR for Outgoing CO Line Callst) → 1.17.5 Time Service—Time Service Switchingu) → 1.11.1 Manager Featuresv) → 1.13.28 PT Programmingw) → 1.13.7 PDN (Primary Directory Number)/SDN (Secondary Directory Number) Extension—SDNKey mode, SDN Walking COS, and assigning SDN buttons through PT programmingConditions• Walking COSExtension users can make a call from extensions of a less-privileged COS by using their own COStemporarily. (→ 1.20.1 Walking COS)Programming ReferencesPC Programming Manual2.8.11 [2-7-1] Class of Service—COS Settings2.10.1 [4-1-1] Wired Extension—Extension Settings—Main—COS2.10.10 [4-2-1] Portable Station—Extension Settings—Main—COSPT Programming Manual2.1.8 COS Programming[602] Class of ServiceFeature Manual References2.1 Capacity of System Resources1.3.20 CPC (Calling Party Control) Signal DetectionDescriptionThe Calling Party Control (CPC) signal is an on-hook indication (disconnect signal) sent from an analog COline when the other party hangs up. To maintain efficient utilization of CO lines, the PBX monitors each line'sstatus and when CPC signal is detected on a line, the PBX disconnects the line and alerts the extensionwith a reorder tone.Conditions• CPC signal detection is programmable for incoming CO line calls, and for outgoing CO line calls.• If your telephone company sends signals similar to CPC, it is recommended not to enable CPC signaldetection on outgoing CO line calls.• If CPC signal is detected during a conference call (→ 1.3.16 Conference), the line is disconnected. Theremaining parties stay connected.• If CPC signal is detected during a call between a caller using the Direct Inward System Access (DISA)feature (→ 1.4.7 DISA (Direct Inward System Access)) and an extension or an outside party, the line isdisconnected.