Highly reliable path accommodation design apparatus and method

A path accommodation design apparatus that performs accommodation design for a wavelength path and a sub-λ path in a communication network, the apparatus comprising:

• a first sub-λ path accommodation device that determines whether or not accommodation of the sub-λ path is possible based on a result of search for a first wavelength path which is present in a single-hop logical route, where if the accommodation of the sub-λ path is possible, the first sub-λ path accommodation device makes the first wavelength path accommodate the sub-λ path;
• a second sub-λ path accommodation device that determines whether or not accommodation of the sub-λ path is possible based on a result of search for a second wavelength path which is present in a multi-hop logical route, where for a plurality of accommodable logical routes, the second sub-λ path accommodation device selects a logical route and a physical route based on the number of hops for the logic route, the number of hops for the physical route, and a wavelength use rate and makes the second wavelength path accommodate the sub-λ path;
• a third sub-λ path accommodation device that searches for each physical route as a candidate for the accommodation of the sub-λ path;
• selects a candidate route based on a wavelength use rate from among each physical route obtained by the search;
• and determines whether or not accommodation of a third wavelength path in the selected candidate route is possible, where the third wavelength path is set in a single-hop logical route by allocation of an available wavelength, and if the accommodation of the third wavelength path is possible, the third sub-λ path accommodation device makes the third wavelength path accommodate the sub-λ path;
• and
• a design device that performs a control to make any one of the first sub-λ path accommodation device, the second sub-λ path accommodation device, and the third sub-λ path accommodation device execute the accommodation of the sub-λ path.