title   "Combined Network Usage"
vtitle  "bps"
area    :first

field :up, :color => "green",
               :alias => "Up",
               :data  => "sumSeries(nonNegativeDerivative(mw*.munin.if_*.up))"

field :down, :color => "blue",
               :alias => "Down",
               :data  => "sumSeries(nonNegativeDerivative(mw*.munin.if_*.down))"