CL-FOM100S/FOM135S/FOM100/FOM135 Fiber Optical Modem can modulate G.703 E1 or V.35 signal to single-mode or multimode fiber which extend the transmitting distance of E1 signal greatly. E1 signal support framed and unframed mode. When in framed mode, continuous or discontinuous time-slot can be selected. E1 fiber modem and V.35 fiber modem can be used together. Both of them are widely used in extending user interface in ATM or DDN.Standalone and Rack mount module are both available.