Tunnels in IP Fast Reroute

Abstract

After the failure of a network node or a link, a period of impaired connectivity is experienced until the network reconverges. During this period, specific destinations are not reachable, causing issues specifically with critical and time-sensitive services such as Voice over IP. The process of network reconvergence can last from a few milliseconds to tens of seconds. To address these issues, IP Fast Reroute (IPFRR) mechanisms have been developed. These mechanisms can reroute via temporary alternative backup paths until the network reconverges. Using IPFRR mechanisms, network recovery time is shortened generally to milliseconds. Multiple approaches to IPFRR exist, ranging from selecting loop-free neighbors through tunneling mechanisms. In this paper, we introduce a new idea of tunnel utilization as a prospective IPFRR mechanism.