Z
 
 zero byte time slot interchange (ZBTSI)
 
      A technique used to ensure pulse density for clear channel
      capability.
 
 zero-bit insertion
 
      A technique used to achieve transparency in bit oriented protocols.
      A zero is inserted into sequences of one bits that cause false flag
      direction. Also called bit stuffing.
 
 zero-suppression
 
      Elimination of unimportant zero, i.e. 0.15 is printed as .15.
 
 zip tone
 
      Short dial tone to an ACD agent, which indicates that a call is
      being connected to the agent console.
 
 ZMODEM
 
      A protocol that features a streaming facility that offers higher
      efficiency than XMODEM or YMODEM.
 
 Zone
 
      A network in a series of interconnected networks that are joined
      through bridges.
 
 zoom in
 
      To enlarge a portion of an image in order to see it more clearly or
      make it easier to alter.
 
 zoom out
 
      A distant view of an image; image is viewed more globally, but with
      less detail.