This Recommendation provides architecture and requirements for a link-state realization of ITU-T Rec. G.7715/Y.1706. It identifies protocol-neutral requirements for hierarchical link state routing derived from ITU-T Recs G.8080/Y.1304 and G.7715/Y.1706 in a distributed environment. The distribution of the architectural components is defined in ITU-T Rec. G.8080/Y.1304, and this Recommendation is one realization of the ASON routing architecture.