Hub, switch and routers are names related with the hardware devices that enable that computers to connect to a network. This article will explain what the basic differences between each of these devices, and how to know which one to use in a given scenario.
The hub is an electronic device that is required to interconnect computers on a local network. Its operation is simple compared to the switch and the router: hub receives data from a computer and transmits to others. When this data transfer is running, no other computer on the network can send signals or data. Just computers can send or receive data when all transmissions are completed.
In a hub you can have multiple ports, i.e. inputs to connect network cables for each computer. Generally, there hubs with 8, 16, 24 and 32 ports. The number varies according to the model and manufacturer of the device.
The best feature of these devices is that if one cable is disconnected or broken, the rest of the network continues to fulfill its task. Currently, the hubs are being replaced by the switches due to the small difference in cost between both devices, and most benefit from the switches.
The switch is similar in appearance to the hub, however presents a big difference: the data from the source computer are only sent to the target computer. This is because the switches create a kind of exclusive channel of communication between the source and destination.
Thus, the network is not limited to a single computer in the transmission of information. This increases network performance because communication is always available, except when two or more computers try to send data simultaneously to the same machine. This feature also reduces errors such as data packets collisions, for example. As well as the hub, a switch has multiple ports and number varies with the price and the manufacturer.
The router is a electronic device used in networks of larger size. It is smarter and capable than the switch, because, besides fulfilling the same function, also has the ability to choose the best route to a given data packet must take to reach its destination. It is as if the network was a big city and the router chooses the shortest and least congested route. Hence this name.
Basically there are two types of routers:
Static: This router type is cheaper and is focused on always choose the shortest path for data, regardless of whether the selected route is congested or not.
Dynamic: This type is more sophisticated (and consequently more expensive) as they are able to determine if there are bottlenecks in the network, and from this analysis send data even for a longer route, but faster, avoiding congestion.
Another interesting feature of dynamic routers is that they are capable to perform data compression to increase the transfer rate.
Routers are able to interconnect various networks, and generally work in conjunction with hubs and switches. Usually they have extra resources, such as firewall, for example.
For those who want to set up a small network, connecting, for example, three computers, use of switches is most recommended as the price of these devices are substantially equivalent to those of hubs. If you share broadband internet, a switch may provide more stable connection.
An important fact: when looking hubs, switches or routers, always choose known brands. That can prevent future problems.
The implementation of routers is generally used in company networks (corporate networks). Besides being more expensive, they are also more complex to be managed, and should only be used if there are many computers on the network.
However, many users with Internet access via ADSL manage their routers and modems to share the Internet connection with all computers on the network, without the computer has to be on, only the modem or router.