UGN Security Forums UGN Security: Underground General Phreaking Can anyone help me to understand A (pbx)private Branch Exchange

Hello,
Well if anyone out there has any spare time to help me out I would greatly Appreciate it. I only have two questions
1: What's a private Branch Exchange (what's it do where it's used)
2: What is a trunk.
Well thank you for time and again thank you. Till then....

Short for private branch exchange, a private telephone network used within an enterprise. Users of the PBX share a certain number of outside lines for making telephone calls external to the PBX.

http://www.webopedia.com/TERM/P/PBX.html


A communications channel between two points. It usually refers to large-bandwidth telephone channels between switching centers that handle many simultaneous voice and data signals.

http://www.webopedia.com/TERM/t/trunk.html