Dark Fiber
Fiber Characterization is a suite of tests performed using connections from both ends of a fiber span. Therefore, fibers need to be unplugged from any equipment and the fiber should be clearly marked as the fiber pair to be tested for FC testing.
Active Fibers
Since Fiber Characterization can not be completed on active fibers, it is generally required that the fibers be scheduled and rolled to a second fiber pair during a maintenance window. This means that fiber testing most likely will need to be completed between the hours of 12 am to 5 am. Additionally, a Methods of Procedures (MOP) will likely need to be reviewed and approved by the network operator to ensure that the traffic affected will is not critical in nature.