There are numerous types of plugs and sockets to connect optical fibers, using threaded, bayonet, push-pull and snap-lock connections. The first fiber-optic connector to be standardized was SMA, which was followed by the SC, ST and FC types. Since most optical transmissions require two cables (one to transmit and the other to receive), smaller form factors such as the snap-lock Fiber Jack were developed to make installations as simple as plugging in a telephone.Not As Easy as CopperAttaching a connector to an optical fiber takes more work than copper wire connectors (note the several steps in the illustrations below). The ends of the fiber usually have to be carefully cemented and then polished in order to let the maximum light pass through. Most class time on the subject is "hands on." See mechanical splice and fusion splice.