interface types for switches--physical illustration

As the main connection device of LAN, Ethernet switch becomes one of the most popular network equipments, meanwhile, with this kind of rapid development, the function of the switch is continuously enhanced, then the replacement of switch port and the connection port of various special equipment are added to the switch continuously. This also makes the switch's interface types become very rich, in order to give you a clearer understanding of these interfaces, we have compiled a special article on the Switch interface:

1, RJ-45 interface

This interface is our most common network equipment interface, commonly known as "Crystal Head", the professional term for the RJ-45 connector, belong to the twisted-pair Ethernet interface type. RJ-45 plugs can only be inserted along a fixed direction, with a plastic shrapnel and RJ-45 slots jammed to prevent falling off.

This interface can be used in 10base-t Ethernet, 100BASE-TX Ethernet, 1000BASE-TX Ethernet, transmission media are twisted pair, but depending on the bandwidth of different media also have different requirements, especially 1000BASE-TX Gigabit Ethernet connection, At least use the Super five line, to ensure the stability of high speed, but also to use 6 types of line.

2, SC Fiber interface

SC fiber interface in the 100BASE-TX Ethernet era has been applied, so it was called 100BASE-FX (F is the abbreviation of optical fiber word fiber), but because the performance is not more than the twisted pair, but the cost is higher, so not be popularized, now the industry vigorously promote gigabit network, SC fiber interface is valued again.

There are many types of fiber interface, SC Fiber interface is mainly used for local network Exchange environment, this interface is provided on some high-performance gigabit switches and routers, and it looks very similar to the RJ-45 interface, but the SC interface is more flat, and the obvious difference is that the inside of the contact, if it is 8 thin copper contacts, Is the RJ-45 interface, and if it is a copper column, it is the SC fiber interface.

3. FDDI interface

FDDI is the most mature LAN technology in the highest transmission rate, with the characteristics of the timing token protocol, supporting a variety of topologies, transmission media for optical fiber. Optical Fiber Distributed Data Interface (FDDI) is a set of protocols that are developed by the United States National Standardization Organization (ANSI) to send digital signals on optical cables. FDDI uses a dual-loop token, with a transmission rate of up to 100Mbps.

CCDI is a variant of FDDI, which uses twisted-pair copper cables as a transmission medium with a data transmission rate usually 100Mbps. FDDI-2 is an extended protocol for FDDI that supports voice, video, and data transmission, and is another variant of FDDI, called FDDI Full-duplex (FFDT), which uses the same network structure as FDDI, but with a transmission rate of up to 200Mbps.

As the use of optical fiber as a transmission media has a large capacity, long transmission distance, anti-interference ability and many other advantages, often used in the metropolitan Area Network, Campus environment backbone network, multiple building network distribution environment, so FDDI interface in the network backbone switch is more common, now with the popularity of gigabit, Some high-end gigabit switches are also starting to use this interface.

4, AUI interface

AUI interface is specifically used to connect the coarse coaxial cable, the earlier network card with such an interface with hubs, switches connected to the network, now generally used.

The AUI interface is a "D" type 15-pin interface, previously used in token-ring or total-line networks, and can be connected to the 10BASE-T Ethernet network with the help of an external transceiver (AUI-TO-RJ-45).