Summary of various interface knowledge on network switches


Introduction to various types of switch interfaces that […]

Introduction to various types of switch interfaces that weak current workers may encounter in actual work.
1. RJ-45 interface
This kind of interface is our most common network device interface, commonly known as "crystal head", the professional term is RJ-45 connector, which belongs to the twisted pair Ethernet interface type. The RJ-45 plug can only be inserted in a fixed direction, and a plastic shrapnel is provided to block the RJ-45 socket to prevent it from falling off.
This kind of interface can be used in 10Base-T Ethernet, 100Base-TX Ethernet, and 1000Base-TX Ethernet. The transmission medium is twisted pair. However, depending on the bandwidth, there are different requirements for the medium, especially 1000Base- For TX Gigabit Ethernet connection, at least Cat 5e cable should be used, and Cat 6 cable should be used to ensure stable high speed.
2. SC fiber interface
The SC optical fiber interface has been used in the 100Base-TX Ethernet era, so it was called 100Base-FX (F is the abbreviation of fiber). However, because the performance was not more prominent than the twisted pair cable but the cost was higher at that time, so It has not been popularized. Now the industry is vigorously promoting the gigabit network, and the SC optical fiber interface is receiving attention again.
There are many types of optical fiber interfaces. SC optical fiber interfaces are mainly used in local network switching environments. This type of interface is provided on some high-performance Gigabit switches and routers. It looks very similar to the RJ-45 interface, but the SC interface appears flatter The obvious difference is the contact piece inside. If it is 8 thin copper contacts, it is an RJ-45 interface, if it is a copper pillar, it is an SC fiber interface.
3. AUI interface
The AUI interface is specially used to connect thick coaxial cables. Early network cards had such interfaces to connect with hubs and switches to form a network, which is generally not used now.
The AUI interface is a "D" 15-pin interface, which was previously used in a token ring network or a bus network. It can be connected to a 10Base-T Ethernet network with the help of an external transceiver (AUI-to-RJ-45) Connection.
4. FDDI interface
FDDI is the highest transmission rate among the current mature LAN technologies. It has the characteristics of a timing token protocol, supports a variety of topological structures, and the transmission medium is optical fiber.
The Fiber Distributed Data Interface (FDDI) is a set of protocols developed by the American National Standards Institute (ANSI) to send digital signals on optical cables. FDDI uses dual-ring tokens, and the transmission rate can reach 100Mbps.
CCDI is a variant of FDDI, which uses twisted-pair copper cable as the transmission medium, and the data transmission rate is usually 100Mbps.
FDDI-2 is an extended protocol of FDDI, which supports voice, video and data transmission. It is another variant of FDDI, called FDDI full duplex technology (FFDT). It uses the same network structure as FDDI, but the transmission rate can reach 200Mbps .
Since the use of optical fiber as a transmission medium has many advantages such as large capacity, long transmission distance, and strong anti-interference ability, it is often used in metropolitan area networks, campus environment backbone networks, and multi-building network distribution environments, so the FDDI interface is in the network backbone switch The above is more common, and now with the popularity of Gigabit, some high-end Gigabit switches are also beginning to use this kind of interface.
5. Console interface
We know that this interface is used to configure switches, so it is only available for managed switches. Also note that not all network-managed switches have it, because there are many ways to configure the switch, such as through Telnet command line, Web, TFTP, and so on.
But it should be noted that the Console port used for switch configuration is not the same for all switches, and some use the same RJ-45 type Console interface as the Cisco router.

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