Infinera CATR Huawei Alcatel-Lucent Ericsson Recent progress in ITU-T Recommendation G.709 standardization has introduced new ODU containers (ODU0, ODU4, ODU2e and ODUflex) and enhanced Optical Transport Networking (OTN) flexibility. Several recent documents have proposed ways to modify GMPLS signaling protocols to support these new OTN features. It is important that a single solution is developed for use in GMPLS signaling and routing protocols. This solution must support ODUk multiplexing capabilities, address all of the new features, be acceptable to all equipment vendors, and be extensible considering continued OTN evolution. This document describes the extensions to the Generalized Multi- Protocol Label Switching (GMPLS) signaling to control the evolving Optical Transport Networks (OTN) addressing ODUk multiplexing and new features including ODU0, ODU4, ODU2e and ODUflex.