An M/G/1 Model for Gigabit Energy Efficient Ethernet Links With Coalescing and Real-Trace-Based Evaluation

In this paper, we analytically model the behavior of gigabit Energy Efficient Ethernet (EEE) links with coalescing using M/G/1 queues with sleep and wake-up periods. The particularity of gigabit EEE links is that energy-saving operations are triggered only when links are inactive in both transmission directions. Our model approximates with a good accuracy both the energy saving and the average packet delay by using a few significant traffic descriptors. Furthermore, we use real traffic traces to investigate on the performance of static as well as dynamic coalescing schemes. Surprisingly, our evaluation shows that dynamic coalescing does not significantly outperform static coalescing.