The Network Planning for LSP Protection in PTN

PTN (Packet Transport Network) can support end-to-end connections and various services for tenants. It employs Label Switching Path (LSP) technology to serve tenants and utilizes LSP protection to ensure service reliability. However, PTN planning stage is critical and the associated LSP problem is unexplored. We formulate the LSP protection problem as an integer linear programming (ILP) model. The objective is to minimize the utilized bandwidth to serve the given tenant service requests, and satisfy non-same-node and non-same-board constraints. However, the ILP can not achieve an optimal solution within reasonable time. To solve the problem, a fast heuristic algorithm, that is, most request demand ordering (MRDO) is proposed to obtain a sub-optimal solution. The simulation results represent that an optimal solution can be obtained by ILP in small PTN topologies, whereas MRDO achieve a sub-optimal solution in large PTN topologies. The results also indicate that MRDO provides a more efficient solution than a baseline algorithm.