PS: Periodic Strategy for the 40-100Gbps Energy Efficient Ethernet

The 40-100Gbps Energy Efficient Ethernet (EEE) standardized by IEEE 802.3bj contains not only the DeepSleep mode, which is 10% of the normal power consumption, but also the FastWake mode, which has much less state transition time and 70% of the normal power consumption. Correspondingly, the strategy of determining the state transitions is crucial to both the power consumption and the incurred latency of frames. As EEE applications always place tail latency constraint on frame transmission, existing strategies for the 40-100Gbps EEE are rarely configured with proper parameters for good power saving under the given tail latency constraint, especially in face of the variable traffic load. To address this problem, we design the Periodic Strategy (PS) for the 40-100Gbps EEE. Specifically, PS works periodically and optimizes the power saving independently in each cycle. In this way, PS decouples the latency constraint and energy saving. 1) It limits the largest incurred latency by the length of the cycle to satisfy the given latency constraint. 2) It achieves good power saving by selecting the proper low power state based on the prediction of incoming frames and entering the selected state just once in each cycle. What’s more, the good performance of PS is insensitive to the traffic pattern. Extensive simulations confirm that PS achieves better energy saving than all the existing strategies under the given latency constraint, under several kinds of different traffic patterns.