In many-to-one approach, a PLR maintains a single backup path to protect a set of primary LSPs traversing the triplet (PLR, facility, MP). Thus, fewer states need to be maintained and refreshed which results in a scalable solution.
In a many-to-one approach, a PLR provides a single backup path for a set of primary LSPs traversing the triplet (PLR, facility, MP). This simplifies state management and enhances scalability.