Delay reduction in redundant trees for preplanned protection against single link/node failure in 2-connected graphs

Protection and restoration in high speed networks is an important issue, especially for applications in SONET and WDM networks. We study quality of service issues in preplanned recovery using redundant trees in 2-vertex connected graphs and 2-edge connected graphs. In particular, we present efficient heuristic algorithms for finding a pair of working-protection trees with small delay in the working tree. Extensive computational results show that our algorithms reduce the average delay in the working tree by 60% to 90%. Many challenging problems remain open.