An optimization Algorithm for the Same Primary and Backup Routing of Label Switching Path Based on KSP in PTN

The optimization of the transport networks can not only make the network structure more reasonable, but also reduce all kinds of unexpected scenarios in the network operation, improving the network efficiency and reducing the failure rate. Packet transport network (PTN) employs Label Switching Path (LSP) technology, including primary and backup routing. When the primary routing fails, the service can be switched to the backup routing, which protects the service and avoids the interruption of the service. However, the unreasonable configuration of the backup routing will cause the same primary and backup routing problem. That is, the primary and backup routings share the same network node or the same board. Once the network node or the connected fibers fail, the two fibers will be interrupted at the same time, causing the protection of backup routing to fail. To solve the problem, an optimization algorithm for the same primary and backup routing of LSP is proposed. The essence of the optimization algorithm is to search the existing routing using K-shortest path (KSP) between two network nodes as backup routing for LSP protection. Through experiments on the PTN of Xianning Mobile Company, the optimization algorithm can improve the network LSP protection rate by 24%, reducing the risk of failure in service transportation effectively.