## Conferencing Call Considerations

This section provides information about conference call behaviors to consider when administering the call server. The telephone application presents a user interface, based in part on the deduction of the call state. But, as the administrator, be aware that the following server-based features can interact with the user interface resulting in a call state that might need explanation:

- When the system parameter Abort Conference Upon Hang-up is set to Yes, the user must dial and press the Complete softkey for the conference to be completed. When the system parameter Abort Conference Upon Hang-up is set to No, the user can hang up immediately after dialing and the conference proceeds normally.
- When the system parameter No Dial Tone Conferencing is set to No, and the Conference or Add softkey is pressed, the call server automatically selects an idle call appearance for the user to dial on. This action allows the next conferee to be added. When the system parameter No Dial Tone Conferencing is set to Yes, the user must manually select a call appearance after pressing the Conference or Add softkey.

Conferencing behavior changes significantly when Select Line Conferencing is set to Yes, which automatically sets No Dial Tone Conferencing to Yes. Specifically:

- If the user finishes dialing the intended conferee, pressing the initial call appearance allows the conference to proceed normally, as if the Join softkey was pressed.
- If the user has not finished dialing the intended conferee, pressing the initial call appearance (placed on soft hold when Conference or Add was pressed) cancels the conference set up.
- If the user presses the Conference or Add softkey, then immediately presses a hard-held call appearance, the previously held call appearance is retrieved from hold and joins the existing conference.

When the system parameter Select Line Conferencing is set to No, the user cancels the conference setup by pressing the call appearance on soft hold before pressing Join. Selecting a hard-held call appearance during conference setup establishes the held call as the intended conferee. If the user is in conference setup and answers an incoming call, the incoming call is established as the intended conferee, but Join must then be pressed. If the user does not want the incoming call to be part of the conference, the call should not be answered, or the call can be answered and then hung up before continuing the conference setup. Pressing an in-use call appearance during conference setup makes that call appearance the intended conferee. The Toggle Swap feature works for Conference setup just like it does for Transfer Setup. For more information, see the last paragraph of Call Transfer Considerations.