最短経路木を利用した省電力経路制御における集約ルータ/転送経路選択方式

摘要

As the Internet grows explosively, power consumption of network components is also increasing, thus network greening becomes the most important issue. When the utilization of some links/routers are relatively low and traffic flows transmitted on them can be detoured via other paths, it would be effective for energy saving of these links/routers to cut off/change their states to low-power activation. In EAR(Energy Aware Routing), traffic is aggregated on the links which are partial/full components of the shortest path trees of appropriate nodes so-called exporter routers and its neighbor routers use these links to transmission. Although this scheme can cut off some links connected with the neighbor routers, it could not for links of any other routers. Thus, in this paper, we propose the extended scheme of EAR in which whole routers use the shortest path trees of representative routers, and show the effectiveness of the scheme compared with both power-saving and communication performance of EAR. We also investigate the determination policy of representative routers and the path selection policy among paths with same cost.%近年のインターネット普及拡大に伴う消費電力の増加により，ネットワークの省電力化は急務である.その手法として低利用率のリンク/ルータを経由するフローを迂回して低消費電力状態に（もしくは切断）し，他経路にトラヒックを集約する方式が有効であり，特定のルータ群（代表ルータ）の最短経路木に集約するEAR(Energy Aware Routing)が提案されている.しかし，この手法では隣接するルータのみが代表ルータの最短経路木を利用するため，省電力効果が不十分である.そこで本研究では，全ルータが代表ルータの最短経路木を利用して経路集約する改善手法を提案し，省電力性能/通信性能を比較して提案手法の有効性を検討する.さらに提案手法において，効果的な最短経路木を構成する代表ルータの決定方針やトラヒック転送時の経路選択方針について調査する.