A method implemented by a software defined network (SDN) controller, the method comprising receiving, from a network node, a request for path optimization, wherein the request comprises information identifying the network node and a destination node, forwarding the request to an application layer traffic optimization (ALTO) server, receiving, from the ALTO server, path information that identifies a plurality of SDN domains to be traversed from the network node to the destination node, wherein the plurality of SDN domains comprises a first SDN domain, in which the SDN controller resides, and a second SDN domain, in which an edge node known by the SDN controller resides, and determining a first path segment from the network node to the edge node.