→ Extension-CO Duration Time (*60s)9.5 [7-5] Miscellaneous— Dial Digits Limitation After Answering—Dial DigitsPT Programming Manual References[472] Extension-to-CO Line Call Duration[473] CO-to-CO Line Call Duration[502] CO Line Call Duration LimitationFeature Manual References3.1.21 COS (Class of Service)3.1.18 ConferenceDescriptionAn extension user can establish a conference call by adding additional parties to an already existing two-partyconversation. This PBX supports three-party through eight-party conference calls. Conferences with more thanfour parties are only possible when a PT or PS user originates the conference.Unattended Conference:The conference originator can leave the conference and allow other parties to continue. Establishing anUnattended Conference allows the originator to return to the conference. Unattended Conferences can onlybe established by PT and PS users.Conditions• When an extension is establishing a conference call the original party is put on hold.• CONF (Conference) ButtonFor a PT/PS which does not have the CONF button, a flexible button can be customized as the Conferencebutton.• Unattended Conference Call DurationThe length of time that a conference call can remain unattended is restricted by the following timers:– Callback Start Timer– Warning Tone Start Timer– Disconnect TimerThese timers behave and operate according to the following chain of events:1. When the unattended conference is established, the Callback Start Timer will begin.2. When the Callback Start timer expires, the Unattended Conference originator’s extension will start toreceive a callback ringing from the PBX and the Warning Tone Start Timer begins.3. When the Warning Tone Start Timer expires, the remaining parties of the conference will start to heara warning tone, the callback ringing will continue to be heard at the Unattended Conferenceoriginator’s extension, and the Disconnect Timer begins.4. When the disconnect Timer expires, the conference is disconnected.If the Unattended Conference originator returns to the conference before the line is disconnected, all timersare cleared.• For a Conference With Six or More PartiesThe EECHO or ECHO card is required. Also the echo canceling function should be enabled through systemprogramming.58 Feature Manual Document Version 2009-123.1.18 Conference
