Verifying configuration in wavelength selective switching node

An apparatus for verifying a configuration of reconfigurable internal optical paths in a wavelength selective optical switching node having at least two wavelength selective switching (WSS) subsystems, each subsystem of the at least two WSS subsystems having at least two internal ports and being configured such that an internal optical path carries traffic from an internal port of an upstream subsystem of the at least two WSS subsystems to an internal port of a downstream subsystem of the at least two WSS subsystems, the apparatus comprising:

• a processing circuit;
• and
• a memory circuit storing computer-executable instructions that, when executed by the processing circuit, configure the apparatus to:
• identify a configuration, comprising a particular upstream subsystem and a particular internal port of a particular downstream subsystem that are coupled to the internal optical path, based on detecting an optical signal distinctive of the particular upstream subsystem and carried to the particular downstream subsystem, the detecting comprising:
• detecting a pattern of wavelengths used for traffic in a first direction, the pattern being distinctive of the particular upstream subsystem, and
• detecting a power of an optical noise source when there is no traffic in a second direction, the power of the optical noise source being distinctive of the particular upstream subsystem, and
• make a record of the identified configuration of the particular internal port of the particular downstream subsystem, wherein the particular internal port of the particular downstream subsystem is coupled to the particular upstream subsystem via the internal optical path,
• wherein the internal optical path is a bidirectional path between the particular upstream subsystem and the particular internal port of the particular downstream subsystem.

A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a processing unit, configure an apparatus to perform operations comprising:

• identifying a configuration, comprising a particular upstream wavelength selective switching (WSS) subsystem and a particular internal port of a particular downstream WSS subsystem that are coupled to an internal optical path, based on detecting an optical signal distinctive of the particular upstream subsystem and carried to the particular downstream subsystem, the detecting comprising:
• detecting a pattern of wavelengths used for traffic in a first direction, the pattern being distinctive of the particular upstream subsystem, and
• detecting a power of an optical noise source when there is no traffic in a second direction, the power of the optical noise source being distinctive of the particular upstream subsystem;
• and
• making a record of the identified configuration of the particular internal port of the particular downstream subsystem, wherein the particular internal port of the particular downstream subsystem is coupled to the particular upstream subsystem via the internal optical path,
• wherein the internal optical path is a bidirectional path between the particular upstream subsystem and the particular internal port of the particular downstream subsystem.