No idea of what precise sort of hardware is there, but the fact is that these cables consist of a bunch of fibers. Dozens of them typically, quick search sugges

No idea of what precise sort of hardware is there, but the fact is that these cables consist of a bunch of fibers. Dozens of them typically, quick search suggests up to 144, but I doubt that's a physical ceiling. So I suppose they make a branch when needed, with some number of fibers going to another direction.