Because a vswitch has many advantages, its application and development speed is much higher than that of a hub. There are various types of vswitches, mainly to meet the needs of different application environments. This article will introduce some mainstream categories of switches.
I. Division from network coverage
1. WAN switches
WAN switches are mainly used in wide-area networks in areas such as the interconnection of telecom man networks and Internet access. They provide basic communication platforms,
2. LAN switches
This type of switch is our common switch and also our learning focus. LAN switches are used in local networks to connect terminal devices, such as servers, workstations, hubs, routers, network printers, and other network devices. They provide high-speed independent communication channels.
In fact, LAN switches can be divided into multiple different types of switches. Next we will continue to introduce the main classification standards for LAN switches,
Ii. Division based on transmission media and transmission speed
According to the network transmission medium used by the switch and the transmission speed, we can generally divide the LAN switch into Ethernet switch, Fast Ethernet switch, Gigabit G bit) Ethernet switch, 10 Gigabit 10G bit) ethernet switch, FDDI switch, ATM switch, and ring switch.
1. Ethernet Switch
The first thing to note is that the "Ethernet switch" here refers to the switch for Ethernet with bandwidth below Mbps, in fact, we will also talk about a "Fast Ethernet switch", "Gigabit Ethernet switch", and "10 Gigabit Ethernet switch" which are actually Ethernet switches, however, they adopt different protocol standards or transmission media, and their interface forms may also be different.
Ethernet switches are the most common and cheap. They are well-equipped and widely used, and can be seen in large and small LAN networks. Ethernet includes three network interfaces: RJ-45, BNC and AUI, the transmission media used are: twisted pair wire, thin coaxial cable and coarse coaxial cable. Do not think that Ethernet is a RJ-45 interface, but twisted pair cable type RJ-45 interface in the network equipment is very common. Of course, the current vswitches cannot be all BNC or AUI interfaces, because currently, the networks using coaxial cables as transmission media are seldom seen, generally, on the basis of RJ-45 interface, BNC or AUI interface is provided to balance the network connection of coaxial cable media. 1 is an Ethernet switch with RJ-45 and AUI interfaces.
Figure 1
2. Fast Ethernet Switch
This type of switch is used for Mbps Fast Ethernet. Fast Ethernet is a network technology that implements Mbps transmission bandwidth on common twisted pair wires or optical fiber cables. It should be noted that fast Ethernet is regarded as a pure port with 10/100 MPs bandwidth. In fact, it is basically Mbps adaptive. In general, this type of Fast Ethernet switch usually uses a pair of wires. Some Fast Ethernet switches may leave a few fiber interfaces "SC" in order to ensure network interconnection with other optical transmission media ". Figure 2 shows a Fast Ethernet switch.
Figure 2
3. Gigabit Ethernet Switch
A Gigabit Ethernet switch is used in a new type of network-Gigabit Ethernet, which is also called a "gigabit (GB) Ethernet ", that's because its bandwidth can reach 1000 Mbps. It is generally used for the backbone network segment of a large network, the transmission medium has two kinds of optical fiber, twisted pair wire, the corresponding interface is "SC" and "RJ-45" interface. Figure 3 shows two Gigabit Ethernet switch products.
Figure 3
4. 10 Gigabit Ethernet Switch
The 10 Gigabit Ethernet switch is mainly used to adapt to the access of the 10 Gigabit Ethernet network. It is generally used on the backbone network segment and uses the optical fiber as the transmission medium. The interface method is also the optical fiber interface. This type of switch is also called a 10G Ethernet switch. At present, 10G Ethernet technology is still in the initial stage of research and development, and the price is very expensive. Generally, it costs 2-9 US $). Therefore, the practical application of 10G Ethernet in various users is not very common, most enterprise users have already adopted a mature Gigabit Ethernet technology, and believe that this speed can meet enterprises' data exchange needs. Figure 4 shows a 10 Gigabit Ethernet switch. It can be seen that it uses all optical interfaces.
Figure 4
5. ATM Switch
An ATM switch is a product used in an ATM network. Due to its unique technical characteristics, ATM networks are currently only widely used in backbone network segments of China Telecom and postal network. Therefore, its switch products are rarely seen in the market. For example, if we use the PPPoA protocol in the ADSL Broadband Access method described below, we need to configure an ATM switch on the local NSP side, the Cable Modem Internet access method of Cable TV also uses an ATM switch at the local end. Its transmission medium generally uses optical fiber, interface type also has two kinds: Ethernet RJ-45 interface and optical fiber interface, these two kinds of interface is suitable for different types of network interconnection. Figure 5 is such an ATM switch. Compared with the inexpensive Ethernet switch, the price of the ATM switch is very high, so it cannot be found in the common LAN.
Figure 5
6. FDDI Switch
The FDDI technology was developed before the rapid Ethernet technology was developed. It mainly aims to solve the limitations of 10 Mbps Ethernet and 16 Mbps token network speed at that time, because its transmission speed can reach 100 Mbps, which is much higher than the first two speeds at that time, there was still a certain market at that time. However, it used optical fiber as the transmission medium at the time, which is much higher than the network cost of Dual-line transmission media. Therefore, with the successful development of the Fast Ethernet technology, FDDI technology also loses its market. For this reason, FDDI devices, such as FDDI switches, are rarely seen. FDDI switches are used in the fast data exchange network of small and medium-sized enterprises in the old age. Their interfaces are all optical interfaces, figure 6 shows a 3COM FDDI switch.
Figure 6
Iii. Application hierarchy
Based on the network layer applied by the vswitch, we can divide the network switch into five types: enterprise-level switch, campus network switch, department-level switch, Working Group switch, and table model switch.
1. enterprise-level switches
Enterprise-level switches are a type of high-end switches. They generally adopt a modular structure and can be used as the backbone of an Enterprise Network to build a high-speed LAN. Therefore, they are usually used at the top layer of an enterprise network.
Enterprise-level switches can provide customized services, priority queue services, and network security control, and quickly adapt to the needs of data growth and change to meet user needs. For networks with more requirements, enterprise-level switches can not only transmit massive data and control information, but also have hardware redundancy and software scalability to ensure reliable network operation. This type of switch clearly shows its own requirements from its location. At least the bandwidth and transmission rate are much higher than the backplane capacity, therefore, enterprise-level switches are generally Ethernet switches over 1 Gigabit. Enterprise-level switches generally use fiber-optic ports to ensure high transmission rates. So what kind of switch can be called an enterprise-level switch? To be honest, there is no clear standard, but we usually think that if it is a backbone switch of an enterprise, the switch that can support more than 500 information points is an enterprise-level switch, 7 shows youxun's modular Gigabit Ethernet switch, which belongs to the enterprise-level switch category.
Figure 7
Enterprise switches can also be connected to a large chassis. This chassis product usually supports many different types of components, such as fast Ethernet and large network relay, FDDI concentrator, licensing ring MAU and router. Enterprise switches are very useful when building enterprise-level networks, especially for network technologies and previous systems that need to be supported. Chassis-based equipment usually has very powerful management features, so it is very suitable for enterprise network environments. However, the cost of chassis-based equipment is very high, and few small and medium-sized enterprises can afford it.
2. Campus Network Switch
Campus network switches, which are rarely used in large networks and are generally used as backbone switches of networks. This type of switch provides fast data exchange capability and full duplex capability, provides intelligent features such as fault tolerance, and supports multiple functions such as expansion options and VLAN in layer-3 switching.
This type of switch is often used for the name of a scattered campus network. In fact, it does not have to be applied to campus networks. It only indicates that it is mainly used in large-scale networks with scattered physical distance. Because the campus network is relatively scattered and the transmission distance is relatively long, in the backbone network segment, such switches usually use fiber or coaxial cable as the transmission medium, of course, the switch also needs to provide SC Optical Fiber port and BNC or AUI coaxial cable interface.
3. Department-level switches
A department-level switch is a switch for a department-level network. It is much smaller than the previous two types of networks. This type of switch can be fixed configuration, can also be module configuration, in addition to common RJ-45 twisted pair interface, also with fiber interface. Department-level switches generally have outstanding smart features and support port-based VLAN Virtual LAN). This allows for port management and any full-duplex or half-duplex transmission mode to control traffic, with the network management function, you can configure, monitor, and test switches through the serial port of a PC or through the network. If it is used as a backbone switch, it is generally considered that the switch of medium-sized enterprises that support the following 300 information points is a department-level switch, as shown in Figure 8 is a department-level switch product.
Figure 8
4. workgroup switches
The workgroup switch is an ideal replacement product for traditional hubs. It is generally fixed and has a certain number of 10Base-T or 100Base-TX Ethernet ports. The switch simply decides to forward information based on the MAC address in each package. This forwarding decision generally does not consider the deeper information hidden in the package. Different from a hub, the forwarding latency of A vswitch is very small, and the operation is similar to the performance of a single LAN, far exceeding the forwarding performance between common Bridging networks.
Working group switches generally do not have the network management function. If they are used as backbone switches, they are generally considered to support switches within 100 information points as working group-level switches. 9 shows a Fast Ethernet workgroup switch.
Figure 9
