ALR Switching and Routing Strategy for Multiple Sites Based on Traffic Splitting Method for Power Saving.

In recent years, researchers have focused on methods to reduce the network devices' energy consumption since it is increasing rapidly with the growth of internet traffic. Uchida et al. proposed an ALR (Adaptive Link Rate) switching method for OpenFlow networks based on the traffic splitting method. Their method split the traffic to a bypass based on DSCP field so that the link on the shortest path can remain low speed when the traffic is at an “intermediate” rate. However, the method merely considered the situation where only one site communicates with a different site which has a gateway into the Internet. When multiple sites in the same organization network adopt this method, a conflict will be caused since the bypass may not only be a bypass but also be the shortest path for other sites. To solve this problem, this paper extends the method by assigning the switches to one of four states to avoid possible conflict in the bypass so that multiple sites can communicate with a host via the gateway at the same time. The results show that power consumption is reduced by 5.30% compared to the general ALR and 12.39% compared to the normal network.