Puzzling over telecom terms—but you don't know who to ask? Here's help and hard answers to a wide range of questions. What's full duplex? What do PBX and KSU mean, and what's the difference between analog and digital? Now you'll have the information you've always wondered about.

And, if you have any questions that aren't covered by one of our HelloHints, please let us know. We're here to help. Just e-mail us at xpressit@hellodirect.com.