In today’s global networked era, the Internet has become a must for human life. As an important device for the establishment of local area networks: switches and hubs, they all play the role of a “transport” for data transmission in the local area network. So what is the difference between a switch and a hub?
The so-called switch is actually derived from the hub technology. If the difference between a switch and a hub is described in the simplest language, it should be the difference between smart and non-intelligent. The hub says that it is only a device that connects multiple computers. It can only amplify and transmit signals, but it cannot process the fragments in the signal, so it is very error-prone during transmission. The switch can be seen as an intelligent hub, which includes all the features of the hub, as well as automatic addressing, switching, and processing functions. In the process of transmission, only the sending source and the receiving source work independently, and there is no relationship with other ports, thereby preventing data loss and improving throughput.
Next, I will analyze the differences between the two concepts, such as the concept, type, characteristics, OSI architecture, and working methods of the switch and hub.
1. The concept of switches and hubs
1.1 The English name of the switch is called “Switch”. It is an upgraded product of the hub. From the appearance point of view, it is basically not much different from the hub. It is a rectangular box with multiple ports. The switch is a technical term for sending the information to be transmitted to the corresponding route that meets the requirements by means of manual or automatic completion of the information according to the needs of both ends of the communication. A generalized switch is a device that performs information exchange functions in a communication system.
1.2 Hub Hub (HUB) is a connected device that connects multiple computers or other devices in a computer network and is the smallest unit for centralized management of the network. The English HUB is the meaning of the center. Like the trunk of a tree, it is the collection point of each branch. Many types of networks rely on hubs to connect devices and distribute data to various segments. The HUB is basically a shared device, which is essentially a repeater that mainly provides signal amplification and relay functions. It distributes all signals received by one port to all ports.
2. Types of switches and hubs
Switches and hubs have different classifications from different aspects and perspectives.
2.1 Types of HUB Hubs
There are many types of hubs, each with specific functions and offering different levels of service.
2.1.1 According to different bus bandwidths, HUB is divided into 10M, 100M and 10M/100M adaptive; if it is different according to the configuration form, it can be divided into three types: independent type, modular type, and stacked type.
2.1.2 There are mainly 8 ports, 16 ports and 24 ports depending on the number of ports.
2.1.3 According to the working mode, it can be divided into intelligent and non-intelligent. The HUB currently used is basically a combination of the first three categories, such as the 10M/100M adaptive smart type, stackable HUB that we often see in advertisements.
2.1.4 Differentiated according to the working mode, it can be further divided into four types: passive hub, active hub, smart hub, and switching hub.
2.2 Classification of switches
2.2.1 According to the current complex network configuration, network switches are divided into access layer switches, aggregation layer switches, and core layer switches. Among them, the core layer switches all adopt the chassis type modular design. At present, the 1000BASE-T modules equipped with them are basically designed. The purchase of the core layer switches is not discussed in this paper. The Ethernet switch supporting the 1000BASE-T at the access layer is basically a fixed port switch, which is mainly a 10/100 Mbps port, and provides a 1000BASE-T uplink port in a fixed port or an expansion slot. The aggregation layer 1000BASE-T switch has two types of chassis type and fixed port type, and can provide multiple 1000BASE-T ports. Generally, other types of ports such as 1000BASE-X can also be provided. The access layer and the aggregation layer switch together form a complete small and medium-sized LAN solution.
2.2.2 According to the OSI 7-layer network model, the switch can be divided into a second layer switch, a third layer switch, a fourth layer switch, etc., up to the seventh layer switch. Layer 2 switches based on MAC address work are most common and are used in the network access layer and aggregation layer. Layer 3 switches based on IP addresses and protocols are commonly used in the core layer of the network and are also used in small amounts in the aggregation layer. Some Layer 3 switches also have a Layer 4 switching function, which can perform target port judgment based on the protocol port information of the data frame. Switches above the fourth layer are called content switches and are mainly used in Internet data centers, and are beyond the scope of this article.
2.2.3 According to the manageability of the switch, it can be divided into a manageable switch and a non-manageable switch. The difference is that it supports SNMP, RMON, and other network management protocols. Manageable switches facilitate network monitoring, but at a relatively high cost. Large and medium-sized networks should choose manageable switches at the aggregation layer. Depending on the application needs, the core layer switches are all manageable switches.