data channel

from The Free On-line Dictionary of Computing (8 July 2008)

data channel

   <communications> A channel (on a {BRI} or {PRI} line) used to
   carry control information, to set up connections on the
   associated {bearer channels}.  The name wasn't too bad back
   when users were sending voice (not data) over the {bearer
   channels}, but in 1997 it's quite a misnomer.

   (1997-03-10)