
190 Architectural Design of an Energy-Efficient Router
(a) traditional
(b) power-aware
Figure 7.2: Different traffic engineering goals.
US education backbone, as an example. It is shown that the average link
utilization is only about 2%; the maximum fluctuates mostly between 10%
and 20%; and only one rare event pushes the maximum over 50% [20]. High
path redundancy and low link utilization combined also provide a unique op-
portunity for power-aware traffic engineering. Traditional traffic engineering
spreads the traffic evenly in a network (Fig. 7.2a), trying to minimize the
chance of congestion induced by traffic bursts. However, in power-aware traf-
fic engineering ...