1. What type of headset jack is that the SMT5100 uses. I have found the headset that comes witht he phone to be quite poor and I am hoping that it is not a proprietary jack or at least a converter of some type exists.

2. How in the world can you retrieve a call placed on hold from a standard desk phone on the SMT5100? Simply typing the line number like you would do to access the outside line gives an already in use message.