The operation of optical networks requires information on the physical characterization of optical network elements, subsystems, devices, and cabling. These physical characteristics may be important to consider when using a GMPLS control plane to support path setup and maintenance. This document discusses how the definition and characterization of optical fiber, devices, subsystems, and network elements contained in various ITU-T recommendations can be combined with GMPLS control plane protocols and mechanisms to support Impairment Aware Routing and Wavelength Assignment (IA-RWA) in optical networks.