Traditional OLP protection requires four valuable core resources. However, in many places, due to insufficient fiber resources, it is impossible to provide excess fiber resources and optical line redundancy protection. In view of the shortage of optical fiber resources and need to optical line redundancy protection, our company has developed BIDI OLP equipment to solve the problem of optical line protection in the case of insufficient optical cable resources. OLP-BIDI only needs two fibers to realize the optical line protection function. When the main circuit fiber fails, the receiving end automatically switches to the standby fiber receiving, ensuring communication without blocking operation, improving communication system stability and reliability. It also saves fiber resources. Optical line protection switch provides both Manual and Automatic switching mode. In Manual mode, the system switches optical path only based on the commands from user. In the Automatic mode, the system switches based on the power level detected and the preset threshold. Under automatic mode, the system can be set to be revertive or Non-revertive modes. Under Revertive mode, the system switches back to the working path automatically after the fault condition is cleared. Under Non-revertive mode, the system does not switch back.The OLP models fit HT6000 Series CH04, CH08, CH20 Chassis.