The capability to compute end-to-end paths across multiple optical domains, or inter-domain path computation, is an essential requirement in the continued evolution of today's optical transport networks. The key technologies and network conditions required for end-to-end multi- domain services exist, but, they are not ideal and will require further development to meet network operator requirements. This paper describes the enabling International Telecommunication Union (ITU-T) and Internet Engineering Task Force (IETF) architectures and technologies that can be combined to achieve path computation for end-to-end connectivity in multi-domain optical transport environments.

This paper also outlines the technical areas that require continued development to enhance existing path computation techniques to provide paths that cross multi-domain optical networks.