SFU (Single Family Unit) single-family unit ONU It is mainly used for single home users in FTTH scenarios and ordinary terminals that only support broadband access. Generally, it has 1 to 4 Ethernet interfaces and provides Ethernet / IP services. The built-in optical equipment or IAD equipment can support CATV services or VoIP business. Now often used in conjunction with home routers to provide greater business capabilities. HGU (Home Gateway Unit) Home gateway unit type ONU It is mainly used for single home users in FTTH occasions. Compared with SFU, which has the function of home gateway, it is equivalent to a home gateway with PON uplink interface. It generally has 2 ~ 4 Ethernet interfaces, 1 WLAN interface and 1 USB interface. Provide Ethernet / IP services, through the built-in optical or IAD devices can support CATV business or VoIP services, support TR-069 remote management. MDU (Multi.Dwelling Unit) multi-family unit ONU Mainly used in FTTB / FTTC / FTTCab mode for multiple residential users occasions, with broadband access terminal functions, usually with at least 4 user-side interfaces in the telecom operators equipment selection, often including Ethernet interfaces, ADSL2 + Interface or VDSL2 interface to provide Ethernet / IP services. In the radio and television operators of the network applications, due to differences in business content, generally only contains the Ethernet interface for PON + LAN access. MTU (Multi-tenant Unit) Multi-tenant unit type ONU It is mainly used for multiple enterprise users in the FTTB scenario or multiple individual users in the same enterprise. It has the function of broadband access terminal and has multiple Ethernet interfaces (usually at least eight), E1 interfaces and POTS interfaces, and provides Ethernet Network / IP services, TDM services and VoIP services (built-in IAD). SBU (Single Business Unit) single-business unit ONU Mainly used in the case of FTTO, separate business users and businesses in a single office access. Support broadband access terminal functions, in the telecom operation network, generally with Ethernet interface, E1 interface, VOIP interface, etc., to provide Ethernet / IP services and TDM services.