Fiber TAP cassettse give space for network administrators to plug in monitoring equipment for both troubleshooting and monitoring of the network. Optical data is split off into two parts in a specific split ratio for transmission and tapping/monitoring. Which means there will be a light loss if using a tap patch cassette. For instance, if an optical tap cassette has a split ratio of 90:10, the 90% power light will be used for transmission and the 10% part will be used for monitoring. Complete network visibility requires access to all network segments and often requires multiple copies of the same signal to feed a variety of analytic devices.