3-Party Conferencing is built into the Telephone System. This is essentially a Supervised Transfer except that you stay on the line.
WITH FIRST CALL IN PROGRESS:
Press TRANSFER (DTerm) or FLASH (standard phone) This automatically puts the caller on hold.
Dial the 3rd party to be connected (internal or external number)
Press CONF (DTerm) or FLASH (standard phone) to join all parties.
Note that on newer model DTerms, there is no CONF button. On these, CONF appears in the display after you have the third party on line. Press the button under the CONF in display to connect everyone.
CONFERENCES OVER 3 PARTIES: Contact the Help Desk at 7900 to schedule a telephone conference of up to 14 parties.