Should this work? I dial an external number as a conference party (after an access code is entered), then I hit "Conf" feature button on my 8410 digital phone, the Service-Observing code (e.g. "345") plus the extension to be observed (e.g. "3218"), then hit "Conf" again. I was able to observe the extension, but other parties on this conferenced call was put on-hold and unable to join the Service-Observing session at all. Thanks in advance!