US Patent 9871719 Computing service chain-aware paths

A method implemented by a path computation element (PCE), comprising receiving a path computation request to compute a network path for a source-destination pair in a service chain (SC) network, wherein the path computation request comprises at least one network routing constraint and a service function (SF) input associated with a plurality of SFs, computing a plurality of network paths through the network for the source-destination pair according to the network routing constraint, selecting at least a first of the network paths according to the SF input, and sending a path computation response indicating at least the first network path in response to the received path computation request.