Fiber Driver T1/E1 multiplexers extend the distance, functionality, and management of copper networks while optimizing the use of the existing fiber optic plant. They use advanced Time Division Multiplexing (TDM) technology to combine T1 or E1 and sometimes an Ethernet channel over an SFP-based fiber link. The modules are transparent to framing format, and they support HDB3, AMI, and B8ZS line codes.