Various embodiments of the disclosed subject matter provide methods and systems to generate node-disjoint routing paths from a root node to each node in a network node set, identify potential intermediate office node (IO) candidate pairs from the generated node-disjoint routing paths, generate a per central office node (CO) serving cost estimate for each IO candidate pair, and identify a low cost IO candidate pair having at least two node-disjoint paths to the root node without traversing nodes along a diverse path between the low cost IO candidate pair and subtending CO nodes.