Difference between Hub, Switch and Router

Today, most routers are devices that incorporate multiple functions, and even take on the functions of switches and hubs. Sometimes routers, switches and hubs are combined in one device, and for those who are new to the network it is easy to confuse the functionality of these devices.

Let's start with hubs and switches because both devices have similar roles on the network. Each device acts as a central hub for all network devices, and handles a form of data called "frames". Each frame carries data. When the frame is received, it will be amplified and transmitted to the destination PC's port. The biggest difference between the two devices is the method of distributing data frames.

With a hub, a data frame is transmitted or transmitted to all ports of the device without distinguishing the ports from each other. Transferring the data frame to all hub ports to make sure the data will be transferred to the destination. However, this capability consumes a lot of network traffic and can cause the network to be slow (for poor power networks).

In addition, a 10 / 100Mbps hub must share bandwidth with all its ports. So when only one PC transmits broadcast, the hub still uses its maximum bandwidth. However, if multiple PCs broadcast data, still some of this bandwidth is used, and will have to be broken down to reduce performance.

Meanwhile, the switch keeps a record of the MAC address of all the devices it connects to. With this information, the switch can determine which system is waiting at which port. When receiving a data frame, the switch knows exactly which port to send, maximizing the network response time. And unlike hubs, a 10 / 100Mbps switch will deliver a full 10 / 100Mbps rate for each device port. So with the switch, no matter how much data the PC transmits, users will always get the maximum bandwidth. That's why the switch is considered a better option than a hub.

The router is completely different from the above two devices. While hubs or switches involve data frame transmission, the main function of the router is to route packets on the network until they reach the final destination. One of the important features of a packet is that it contains not only data but also destination addresses.

Routers are usually connected to at least two networks, usually two LANs or WANs, or a LAN and some ISP's network. The router is located at the gateway, which connects two or more different networks. By using header and forwarding tables, the router can decide which path is best to forward packets. The router uses the ICMP protocol to communicate with other routers and helps to configure the best route between any two hosts.

Today, there are many services that are attached to broadband routers. Typically, a router consists of a 4-8 Ethernet switch port (or hub) and a network address converter - NAT (Network Address Translator). In addition, the router usually includes a Dynamic Host Configuration Protocol (DHCP) server, Domain Name Service (DNS) proxy server, and firewall hardware to protect the LAN from unauthorized intrusion from the Internet.

All routers have a WAN port to connect to a DSL or cable modem - for broadband Internet service, and an integrated switch to make LAN easier. This feature allows all PCs on the LAN to access the Internet and use file and printer sharing services.

Some routers have only one WAN port and one LAN port, designed for connecting an existing LAN hub / switch to the WAN. Ethernet switches and hubs can connect to a router to extend the LAN. Depending on the capabilities (multiple ports) of each router, switch or hub, the connection between the router or switche / hub may require either a straight-line or a loop-through cable. Some routers even have USB ports and many integrated wireless access points.

Some high-end or enterprise routers also include a serial port - to connect to an external dial-up modem, which is very useful in case of a backup of the main broadband connection, and the integration of the printer server. LAN and printer port.

In addition to the protection provided by NAT, many routers also have built-in firewall hardware, which can be configured at the user's request. This firewall can be configured from simple to complex. In addition to the capabilities commonly found on modern routers, the firewall also allows configuring TCP / UDP ports for games, chat services, and many other features.

And so, it can be said briefly: the hub is attached to an Ethernet network component; The switch can effectively connect multiple Ethernet components to each other; and the router can handle all these functions, plus routing TCP / IP packets between LANs or WANs, and of course many other functions.