An apparatus for protection switching in an optical transport network (OTN) includes: a working path interface module configured to check, via a working path for protection switching, connectivity of a first end node and a corresponding second end node; and a protecting path interface module configured to check connectivity of the first end node and the second node via a protection path for protection switching. Upon confirming the connectivity, the working path interface module and the protection path interface module exchange bandwidth resize (BWR) coordination information with each other and simultaneously output an ODUflex bandwidth control signal based on the exchanged BWR coordination information.