How to understand ONU vs. ONT vs. SFU vs. HGU?

ONU (Optical Network Unit), ONT (Optical Network Terminal), SFU (Single Family Unit), and HGU (Home Gateway Unit) are all types of network equipment used in fiber optic networks. Here is a brief explanation of each:

1. ONU (Optical Network Unit): An ONU is a device that is used in a passive optical network (PON) to connect customer premises to the service provider's network. It is typically installed at the customer's location and converts optical signals into electrical signals for use by the customer's devices.

2. ONT (Optical Network Terminal): An ONT is similar to an ONU but is typically used in a point-to-point fiber optic network rather than a PON. It serves the same function as an ONU, converting optical signals into electrical signals for use by the customer's devices.

3. SFU (Single Family Unit): An SFU is a type of network equipment that is typically used in residential settings to provide internet and other services to a single household. It may include a combination of ONU, ONT, and other equipment to deliver services to the customer.

4. HGU (Home Gateway Unit): An HGU is a type of network equipment that combines the functions of a modem, router, and other networking equipment into a single device. It is typically used in residential settings to provide internet and other services to a single household.

In summary, ONU and ONT are specific types of network equipment used in fiber optic networks, while SFU and HGU are broader terms that may encompass a variety of equipment used to provide services to residential customers. Understanding the differences between these terms can help you better understand the equipment and technology used in your network.

ONU (Optical Network Unit)

- Passive device that only receives and transmits optical signals.
- Requires an external ONT to convert optical signals to electrical signals.
- Located at the customer premises, typically inside the home.

ONT (Optical Network Terminal)

- Active device that converts optical signals to electrical signals and vice versa.
- Provides the physical interface for user equipment (e.g., routers, modems).
- Can be located inside or outside the customer premises.

SFU (Service Function Unit)

- Software-defined device that provides advanced network services (e.g., routing, switching, firewall, VPN).
- Can be integrated into an ONU or ONT, or can be a separate device.
- Enables greater flexibility and scalability in network architecture.

HGU (Home Gateway Unit)

- Integrated device that combines the functions of an ONT, router, and modem.
- Provides a single point of access for multiple devices (e.g., computers, smartphones, TVs).
- Offers a simplified user experience and can support advanced features like Wi-Fi 6 and multi-Gigabit speeds.

Key Differences

| Feature | ONU | ONT | SFU | HGU |
|---|---|---|---|---|
| Functionality | Signal conversion | Signal conversion, user equipment interface | Advanced network services | Signal conversion, user equipment interface, advanced features |
| Location | Customer premises (inside) | Customer premises (inside/outside) | Varies | Customer premises (inside) |
| Active/Passive | Passive | Active | Software-defined | Active |
| Integration | Requires external ONT | Standalone | Can be integrated into ONU/ONT | Integrated router/modem |
| Features | N/A | DHCP, NAT, QoS | Routing, switching, firewall | Wi-Fi 6, multi-Gigabit speeds |

Applications

- ONU: Primarily used in fiber-to-the-home (FTTH) networks where the optical fiber terminates at the customer premises.
- ONT: Used in FTTH networks where the optical fiber terminates at the outside of the customer premises.
- SFU: Deployed in networks that require advanced service capabilities and flexibility.
- HGU: Suitable for home networking applications where a single device can provide all necessary functions and features.

ONU vs ONT The main application types of broadband optical fiber access include FTTH, FTTO, and FTTB, and the forms of user side devices vary depending on the application type. The user side device in FTTH or FTTO is used by a single user, called ONT (Optical Network Terminal), and the user side device in FTTB is shared by multiple users, called ONU (Optical Network Unit). Types of ONT ONT also know as optical modem, and it is divided into SFU (Single Family Unit), HGU (Home Gateway Unit) and SBU (Single Business Unit). SFU usually has 1 to 4 Ethernet interfaces, 1 to 2 telephone interfaces, and some models also have cable television interfaces. SFU does not have a home gateway function, and requires a terminal connected through an Ethernet port to dial up for internet access. The remote management function is weak. The optical modem used in the early days of FTTH belongs to SFU, but it is rarely used now. HGU 1.The HGU is a gateway device, which is convenient for home networking. While the SFU is a transparent transmission device without gateway capabilities, and generally requires the cooperation of a gateway device such as a home router when building a home network. 2.HGU supports routing mode and has NAT function. It is a three layer device; while SFU only supports two layer bridge mode, which is equivalent to a two layer switch. 3.HGU can implement its own broadband dial-up application, and the connected computers and mobile terminals can directly access the Internet without dialing. While SFU must be dialed by a terminal such as the user's computer or mobile phone, or dialed through a home router. 4.HGU is much easier for large-scale operation and maintenance management 5.HGU usually comes with wifi and has a USB port. SBU SBU is mainly used for FTTO user access, and generally has an Ethernet interface. Some models have an E1 interface, a fixed telephone interface, or a wifi function. Compared with SFU and HGU, SBU has a better electrical protection performance and higher stability, and is also commonly used in outdoor situations such as video surveillance. Types of ONU ONU is divided into MDU (Multi-Dwelling Unit) and MTU (Multi-Tenant Unit) MDU is mainly used for the access of multiple residential users under the FTTB application type, and generally has at least 4 user side interfaces, usually with 8, 16, 24 FE or FE+POTS (fixed telephone) interfaces. MTU is mainly used for the access of multiple enterprise users or multiple terminals within a same enterprise in the FTTB scenario. In addition to Ethernet interface and fixed telephone interface, it may also have E1 interface. The appearance and function of MTU are usually not the same as those of MDU, but they have better electrical protection performance and higher stability. With the popularization of FTTO, the application scenarios of MTU are getting smaller and smaller. Broadband optical fiber access mainly uses PON technology. When the specific form of user side equipment is not distinguished, the PON system of user side equipment can be collectively called as ONU. https://www.glsun.com/article-p123-onu-vs-ont-vs-sfu-vs-hgu.html