Components The OptiX RTN 950 adopts a split structure. The system consists of the IDU950, the ODU, and the antenna system. An ODU is connected to an IDU through an IF cable. IDU 950 The IDU 950 is the indoor unit of an OptiX RTN 950 system. It accesses services, performs multiplexing/demultiplexing and IF processing of the services, and provides system control and communication function.