Fast Convergence With Fast Reroute in IP Networks

It has been observed that even in well managed networks, failures of links and routers are not uncommon. In order to satisfy the demand for high availability in case of a failure, fast restoration of loop-free forwarding along the optimal paths is imperative for a routing scheme. Failures can be circumvented quickly with local rerouting but packets take potentially long detours. Global recomputation of new optimal routes incurs a convergence delay and can cause forwarding loops during convergence. Attempts to avoid transient loops may also increase the convergence delay.