Network interface refers to various interfaces of network equipment. Almost all network interfaces we are using today are Ethernet interfaces.
The network interface transmission rate is usually 10M/100/1000Mbps and can work in full-duplex or half-duplex mode. Common Ethernet interface types include RJ-45 interface, RJ-11 interface, SC fiber optic interface, FDDI interface, AUI interface, BNC interface, Console interface, etc.
The Internet phone uses the network interface type to connect to the internal LAN. Different networks have different interface types. Common Internet phone interfaces mainly include RJ-45 interface, RJ-11 interface and USB interface.
General Internet phones will provide two RJ-11 interfaces. One RJ-11 interface is used to connect the telephone line connected to the HomePNA switch. Another RJ-11 interface is connected to the telephone.

The RJ-11 plug is the most common wiring method. An RJ-11 plug has six pairs of copper wire connectors at the end, indicated by different colors. Typically only four pairs of copper wires are used.
The four pairs of copper wires used are usually indicated by black, white, red and green. The black and white wires let small signals like phone and light signals go through. The two pairs of copper wires, red and green, are mainly used for voice or data transmission.
The RJ-45 plug is similar in shape and appearance to the RJ-11 plug, but is wider. Because it contains eight terminal copper wire connectors to increase data transmission speed. Therefore, it is our most common port. The RJ-45 port is mainly used to connect the Ethernet card of the computer in Internet phones.
Ethernet primarily uses twisted pairs for transmission. The RJ-45 port is divided into two types based on communication speed: 10Base-T network RJ-45 port and 100Base-TX network RJ-45 port.
The "ETH" label is typically used to identify the RJ-45 port of the 10Base-T network on the router. Similarly, the RJ-45 port of the 100Base-TX network is commonly marked as "10/100bTX". This is primarily due to the fact that the majority of present-day fast Ethernet router products continue to utilize adaptive bandwidth of 10/100Mbps.
The Universal Serial Bus interface functions similarly to the RJ-11 or RJ-45 interface in Internet telephony. Used for taking power on the one hand, and for data transmission on the other hand.
Under the current USB specifications, each port (PORT) can connect 127 devices at the same time. And supports PLUG-AND-PLAY and can do HOT-PLUGGIN without turning off the power). USB is a transmission technology specification.
Currently, 2.0 has appeared, which supports a transmission rate of 480Mbps, which is 480 times that of the current USB 1.1. The first option is faster and works with USB 1.1, so you can still use old USB devices, cables, and connectors.
The above is an introduction to "What is a network interface?"