A Multi-start Variable Neighbourhood Search with a New Solution Construction Method for Solving Inter-Domain Path Computation Problem

Inter-Domain Path Computation under Node-Defined Domain Uniqueness Constraint (IDPC-NDU) is one of the routing cost optimization problems in multi-domain networks that has been proposed and received much attention by researchers. Because the IDPC-NDU is NP-Hard, the approaches using approximation algorithms are frequently used. These approximation algorithms often construct solutions based on connecting edges between adjacent domains, with little consideration of edges between non-adjacent domains. Furthermore, this study investigates how to combine an algorithm with the capability of exploration with another algorithm with the capability of exploiting in order to balance the ability to explore and exploit the search space. As a result, based on new encoding and decoding solution methods, this study proposes combinations of the algorithms Multi-start Method and Variable Neighbourhood Search Method. By considering the inter-domain edges connecting non-adjacent domains, the new encoding and decoding methods help to examine more possible paths between the source node and the destination node. The proposed algorithm is evaluated by comparing it to the most recent algorithms that were proposed to solve the IDPC-NDU. Analysis of experimental results on various instances shows that the proposed algorithm exceeds other algorithms in most of the experimental cases. In particular, one-fifth of the test cases on which the proposed algorithm finds the optimal solution. Besides, the study also analyses the influence of the attributes of the input data on the efficiency of the proposed algorithm.