12 Feature Guide1.13.1.2 Conference .................................................................................................................................................... 1531.13.1.3 Privacy Release............................................................................................................................................. 1551.14 Paging Features ...........................................................................................................1561.14.1 Paging ............................................................................................................................ 1561.15 Broadcasting Features ................................................................................................1581.15.1 Broadcasting ..................................................................................................................1581.16 Optional Device Features ............................................................................................1611.16.1 Doorphone Call ..............................................................................................................1611.16.2 Door Open......................................................................................................................1631.16.3 Trunk Answer From Any Station (TAFAS)....................................................................... 1641.16.4 Background Music (BGM) ..............................................................................................1651.16.5 Outgoing Message (OGM) ............................................................................................. 1661.16.6 Direct Inward System Access (DISA).............................................................................1691.16.7 Automatic Fax Transfer...................................................................................................1771.16.8 Built-in Simplified Voice Message (SVM) ....................................................................... 1791.16.9 External Sensor .............................................................................................................1841.16.10 External Relay Control ...................................................................................................1861.17 Caller ID Features.........................................................................................................1881.17.1 Caller ID .........................................................................................................................1881.17.2 Incoming Call Log ..........................................................................................................1931.18 Message Features ........................................................................................................ 1951.18.1 Message Waiting............................................................................................................1951.18.2 Absent Message ............................................................................................................1981.19 Proprietary Telephone (PT) Features ......................................................................... 1991.19.1 Fixed Buttons ................................................................................................................. 1991.19.2 Flexible Buttons..............................................................................................................2021.19.3 LED Indication................................................................................................................2051.19.4 Display Information.........................................................................................................2081.20 Integrated Services Digital Network (ISDN) Service Features .................................2101.20.1 Integrated Services Digital Network (ISDN) ...................................................................2101.20.1.1 Integrated Services Digital Network (ISDN)—SUMMARY............................................................................. 2101.20.1.2 Calling/Connected Line Identification Presentation (CLIP/COLP)................................................................. 2141.20.1.3 Advice of Charge (AOC)................................................................................................................................ 2161.20.1.4 Call Forwarding (CF)—by ISDN (P-MP) ........................................................................................................ 2171.20.1.5 Call Forwarding (CF)—by ISDN (P-P) ........................................................................................................... 2191.20.1.6 Call Hold (HOLD)—by ISDN.......................................................................................................................... 2211.20.1.7 Call Transfer (CT)—by ISDN ......................................................................................................................... 2221.20.1.8 Three-party Conference (3PTY)—by ISDN ................................................................................................... 2231.20.1.9 Malicious Call Identification (MCID)............................................................................................................... 2241.20.1.10 Completion of Calls to Busy Subscriber (CCBS)........................................................................................... 2251.20.1.11 ISDN Extension ............................................................................................................................................. 2261.20.1.12 ISDN Service Access by Keypad Protocol .................................................................................................... 2281.21 E1 Line Service Features............................................................................................. 2291.21.1 E1 Line Service .............................................................................................................2291.22 T1 Line Service Features............................................................................................. 2311.22.1 T1 Line Service .............................................................................................................2311.23 Voice Mail Features ...................................................................................................... 2331.23.1 Voice Mail (VM) Group ...................................................................................................2331.23.2 Voice Mail DTMF Integration ..........................................................................................2361.23.3 Voice Mail DPT (Digital) Integration ...............................................................................2421.24 Portable Station (PS) Features ...................................................................................2471.24.1 Portable Station (PS) Connection .................................................................................. 2471.24.2 PS Ring Group ...............................................................................................................249