From the conversation, press the Transfer button (the person you were talking with will now be on hold). Listen for dial tone and then enter the desired extension. When the phone begins ringing, you may hang up to complete the transfer. You may also wait for the second party to answer, announce the transfer and then hang up. Hanging up connects the original caller with the party you just called.
From the conversation press transfer button and listen for dial tone. Enter the phone number of the person to which you are transferring. If the line is busy or there is no answer, press the cancel button to return to the original conversation.