Ethernet ultra-fast switching: a tree-based local recovery scheme

Resilience issue in Ethernet is becoming even more important when Ethernet is becoming more pervasive. The authors propose a local recovery scheme, named Ethernet ultra-fast switching (EUFS), to address this issue. EUFS is based on the multiple spanning tree protocol, which is the basics of both load balancing and fast recovery mechanisms in large-scale Ethernet networks. For each node, the authors construct a pair of protection trees rooted at this node. Normally, the traffic is forwarded along the working trees. When a link or node fails, the immediate upstream node switches the traffic, which intends to pass through the failed link or node, from the working trees to one of the protection trees rooted at itself. EUFS has the following features. First, it achieves an ultra-fast recovery from any single failure in two-connected networks. Second, it supports backward compatibility, because switches implementing EUFS can inter-operate with the legacy Ethernet switches.