An activity display for multiple data channels over a period of time for a
communication link provides a quasi-three-dimensional presentation having
time periods and data channels as orthogonal axes and shading within each
time period/data channel rectangle representing ones density for the
channel during that time period. One or more frames of the communication
link corresponding to one time period are captured, and then each frame
is processed in sequence one data channel at a time to build up a line of
the display for the time period. Over multiple time periods the display
is built up line by line, with the oldest line being dropped as a new
line is added when the maximum number of lines for the display is
achieved. In this way an operator has a high level all-in-one glance at
the operation of the communication link.