Patent ID: 7418493

Claim:
In a data communication network, a method for estimating an upper bound of a bandwidth protected by one or more backup tunnels passing through a link, said method comprising: defining constraints on an aggregate flow protected by said one or more backup tunnels, said aggregate flow comprising individual flows corresponding to link pairs traversing a protected node; identifying a primary bandwidth of each link of said link pairs; and maximizing said aggregate flow under said constraints to determine said upper bound, wherein maximizing comprises computing flow maximization with each of said individual flows represented by a flow variable, and subjecting said flow variables to said constraints, said constraints corresponding to bandwidth limits on said link pairs traversing said protected node; wherein said constraints comprise: all of said individual flows of said aggregate flow have bandwidth greater than or equal to zero; for all nodes adjoining said protected node, a sum of bandwidths of flows leaving the adjoining node is less than or equal to said primary bandwidth of the link connecting the adjoining node and said protected node; and for all nodes adjoining said protected node, a sum of bandwidths of flows arriving at the adjoining node is less than or equal to said primary bandwidth of the link connecting the adjoining node and said protected node.