Lightweight IP fast reroute with Tunnel-AT

The demand for faster failure-recovery in pure intra-domain IP networks has led to the development of several IP Fast ReRoute (IPFRR) mechanisms. However, these mechanisms are all either too computationally expensive, or fail to provide satisfiable protection coverage. For these reasons, IPFRR schemes have yet to see widespread commercial deployment. In this paper, we present a new IPFRR mechanism called Tunnel-AT based on incremental SPF algorithm and the concept of Attaching Tree. Tunnel-AT outperforms existing IPFRR mechanisms by providing 100% node protection coverage at a computational cost of less than one full SPF calculation.