Dispersing Hotspot Traffic in Backup Topology for IP Fast Reroute

A backup topology design algorithm for avoiding congestion in IP fast reroute is presented. In IP fast reroute techniques, detour routes are computed by using backup topologies. Reducing the number of backup topologies is the main problem, but some links will become overloaded if the number of backup topologies is reduced. The proposed backup topology design algorithm splits the traffic on high load links to other links by considering network conditions, such as the traffic matrix or topology. The key idea of the algorithm is a new concept called the special node, which has a higher node degree in a backup topology, to handle the backup topology design problem. The effectiveness of the algorithm in terms of maximum link load reduction is quantitatively shown.