As an optical signal progresses along its path it may be altered by
the various physical processes in the optical fibers and devices it
encounters. When such alterations result in signal degradation,
these processes are usually referred to as "impairments". These
physical characteristics may be important constraints to consider in
path computation process in wavelength switched optical networks.
This document provides PCEP extensions to support Impairment Aware
Routing and Wavelength Assignment (IA-RWA) in wavelength switched