Practical periodic strategy for 40/100 Gbps Energy Efficient Ethernet

Abstract

The 40/100 Gbps Energy Efficient Ethernet (EEE) standardized by IEEE 802.3bj contains two power saving states. Correspondingly, the strategy determining the state transitions is crucial to both the power consumption and the incurred latency of frames. However, existing strategies hardly configure proper parameters for consistent good performance of power saving under variable traffic loads in reality. To address this issue, we design Practical Periodic Strategy (PPS) for the 40/100 Gbps EEE. Specifically, PPS periodically optimizes the power saving independently in each cycle. In this way, PPS decouples the incurred latency and the energy saving. (1) It limits the incurred delay by the length of the cycle. (2) It achieves good power saving by selecting a proper low power state based on the estimated traffic load in each cycle. Moreover, PPS is practical for two reasons. First, PPS involves just one cycle length parameter, which can be set according to either the given tail latency constraint or optimized automatically according to the cost function reflecting user preference. Second, the good performance of PPS is insensitive to traffic variation, because the traffic variation is smoothed by the cycles of PPS. Extensive simulations based on NS3 confirm that PPS outperforms existing strategies under different traffic patterns.