Explain the concept of router-root path
The mean router-router path is double the mean router-root path. Number levels of tree with root as 1 and the deepest level as n. The path from root to level n requires n - 1 hops, and 0.50 of routers are at this level. The path from root to level n - 1 has 0.25 of routers and a length of n - 2 hops.