Multi-Flow Optimization Model for Design of a Shared Backup Path Protected Network

Designing optimal shared backup path protected networks is a difficult and time-consuming task, and considerable research has been done to develop near optimal heuristics and algorithms that will solve the SBPP model without extensive computing power, but by definition, such methods are sub- optimal. This paper introduces a slight modification to the SBPP problem that allows it to be optimally solved using conventional ILP techniques. By allowing working and backup paths to follow multiple routes, the new SBPP model eliminates the numerous 1/0 variables in the conventional model. The fundamental characteristics of SBPP remain intact, with the problem altering only slightly but it allows ILP solvers to find an optimal solution in a time measured in seconds to minutes compared to the days or longer needed for conventional models.