Date Added: Nov 2012
IETF has defined IP Fast ReRoute (IPFRR) schemes to enable IP networks with fast failover capability. Fundamentally, failure recovery is achieved by provisioning backup paths on standby network resources to provide traffic rerouting for bypassing a failed device. Unlike survivable network designs, the principle used in designing a green network is the opposite. To minimize energy consumption, traffic engineering techniques are applied to aggregate traffic flows on limited network resources. Thus, the unused network devices can be turned off or put on sleep mode to save power.