what is ONU : Optical Network Unit, which is a terminal device for Optical fiber access.
1.Select to receive broadcast data sent by the OLT;
2.Responding to the ranging and power control commands issued by the OLT; and making corresponding adjustments;
3.Caching the user’s Ethernet data and sending it in the upstream direction in the transmission window allocated by the OLT.
The EPON and GPON ONU device consists of a common functional unit such as a core function circuit, power supply, and management.