We focus on two classes of approaches to calculation of network configuration [2, 3], namely, FUFL and DUFL.
FUFL. The first class is very simple and attractive for network operators .
The thresholds are assigned with the following values: [W.sub.D] = 0.977 and [W.sub.A] = 0.985 for FUFL and [W.sub.L] = 0.4885 and [W.sub.H] = 0.9925 for DUFL.
Figures 5(a) and 5(b) report the total power consumption and the power saving for the testbed running FUFL and DUFL on the logical topology, respectively.
Figures 5(c) and 5(d) report the monitored traffic on logical links when FUFL and DUFL are applied, respectively.
The time [[DELTA].sub.Step3] needed for calculation of network configuration (Step 3 in Figure 1) takes 0.15 s for both FUFL and DUFL.
We show the time taken by network reconfiguration [[DELTA].sub.Step4] in Figure 6 for FUFL and DUFL and for both the parallel and consecutive access of routers (automatic and manual authentication, resp.).
In particular, every time that one of the thresholds is violated (Step 2 in Figure 1), one of the actions is taken according to the calculated (with FUFL or DUFL) network configuration (Step 3 in Figure 1).
We demonstrated the operation of energy saving approaches FUFL and DUFL on a testbed with optical GbE interfaces.