Feature Guide 71.7 Busy Line/Busy Party Features.................................................................................... 611.7.1 Automatic Callback Busy (Camp-on)............................................................................... 611.7.2 Executive Busy Override ................................................................................................. 621.7.3 Call Waiting Tone............................................................................................................. 631.8 Toll Restriction (TRS) Features .................................................................................... 641.8.1 Toll Restriction (TRS)....................................................................................................... 641.8.2 Toll Restriction (TRS) Override by Account Code ........................................................... 681.8.3 Extension Lock ................................................................................................................ 701.8.4 Walking COS ................................................................................................................... 711.9 Automatic Route Selection (ARS) Features ................................................................ 721.9.1 Automatic Route Selection (ARS) ................................................................................... 721.10 Conversation Features.................................................................................................. 781.10.1 Hands-free Operation ...................................................................................................... 781.10.2 Room Monitor .................................................................................................................. 791.10.3 Microphone Mute............................................................................................................. 801.10.4 Headset Operation .......................................................................................................... 811.10.5 Data Line Security ........................................................................................................... 821.10.6 Flash/Recall..................................................................................................................... 831.10.7 External Feature Access (EFA) ....................................................................................... 841.10.8 Outside (CO) Line Call Limitation .................................................................................... 851.10.9 Parallelled Telephone ...................................................................................................... 861.10.10 Calling Party Control (CPC) Signal Detection ................................................................. 871.11 Transferring Features.................................................................................................... 881.11.1 Call Transfer..................................................................................................................... 881.12 Holding Features ........................................................................................................... 901.12.1 Call Hold .......................................................................................................................... 901.12.2 Call Park .......................................................................................................................... 921.12.3 Call Splitting..................................................................................................................... 931.12.4 Music on Hold.................................................................................................................. 941.12.5 Consultation Hold ............................................................................................................ 951.13 Conference Features..................................................................................................... 961.13.1 Conference Features ....................................................................................................... 961.13.1.1 Conference Features—OVERVIEW.................................................................................................................961.13.1.2 Conference ......................................................................................................................................................971.14 Paging Features............................................................................................................. 991.14.1 Paging ............................................................................................................................. 991.15 Optional Device Features ........................................................................................... 1001.15.1 Doorphone Call ............................................................................................................. 1001.15.2 Door Open ..................................................................................................................... 1011.15.3 Doorbell/Door Chime ..................................................................................................... 1021.15.4 Background Music (BGM) ............................................................................................. 1041.15.5 Outgoing Message (OGM) for DISA/UCD ..................................................................... 1051.15.6 Direct Inward System Access (DISA) ............................................................................ 1061.15.7 Built-in Voice Message (BV) .......................................................................................... 1141.16 Caller ID Features ........................................................................................................ 1191.16.1 Caller ID......................................................................................................................... 1191.16.2 Incoming Call Log.......................................................................................................... 1231.17 Message Features ....................................................................................................... 1261.17.1 Message Waiting ........................................................................................................... 1261.17.2 Absent Message............................................................................................................ 1281.17.3 Call Routing for Fixed Line SMS.................................................................................... 129