The so-called optical cross-connector is used to terminate the cable where the cable is pulled: in the base station, data center, server room. A typical cross is a 19" metal box that is mounted on a standard rack; the cable to be terminated is inserted in the back and has a port with a port on the front.
Installation of the optical cross-connector is based on a cross and is placed on the rack, but there may also be FO cross panels, as well as other options that are rarely used. In theory, multiple cables can be connected in a cross-connect, some of which can be spliced together and some that can be connected to a port. Then you'll get something you call "cross-closed", which saves material and stitching. Sometimes this is done when installing the FTTB, but doing so is not desirable because the circuit complexity is increased.
The above is a brief introduction of the working principle of the optical cross connector by Fiber Optic Splice Closure manufacturer, hoping to help those in need.