http://www.rfc-editor.org/rfc/rfc7579.txt
RFC 7579: General Network Element Constraint Encoding for GMPLS-Controlled Networks, G. Bernstein, Y. Lee, D. Li, W. Imajuku, J. Han2015-06-01T23:00:00-00:00This document provides efficient, protocol-agnostic encodings for general information elements representing connectivity and label constraints as well as label availability. It is intended that protocol-specific documents will reference this memo to describe how information is carried for specific uses.