The function of the Connection Module CMX is to connect the filters in two ONS 15252 Multichannel Units (MCU). The CMX is, in principle, a Bridge module (BM) with longer fibers. The CMX is used to pass traffic on wavelengths not dropped in the first ONS 15252 MCU to the second ONS 15252 MCU and vice versa. The CMX connects A-side filter banks in one chassis to B-side filter banks in another chassis. This crossover is needed for systems using more than 16 Client Layer Interface Port (CLIP) boards in the MCU. If the CMX is not used, the MU connectors on the last HFM modules can be terminated by replacing the CMX with two Termination modules (TM).