Routers, Modems, Switches and Hubs

Networking devices can be confusing as they all look the same, but perform different roles. The purpose of this blog is to help you understand some of the roles that these devices play in your network. Below I’ve listed the purpose of the most commonly found networking devices.

Router:

A Router is a device that is used to connect at least two networks together and then to route data between them, functioning as a gateway device for the networks. They primarily deal with IP addresses as they route data packets over an internet connection, unlike switches which use MAC addresses to direct packets. A router will not function without a modem but many modern routers function as a modem and a switch, to allow for a physical or wireless network connection to your internet service provider (ISP).

Modem:

Modems are devices that serve as a physical bridge between an ISP and a user’s local network, converting the analogue signal to digital. Typically, this connection will be through a phone line (DSL), coaxial cable, or a fibre connection (ONT). It’s necessary to convert the signal into one that the router is able to understand.

Switch:

Switches are used to process data packets/frames being sent between multiple devices on a network. Frames are processed by looking at MAC addresses, then a MAC address source table is created so the frames can be processed properly and sent to the correct device on the network. This method of sorting data packets means that traffic on a network can be reduced as data will only be sent from one device to another, taking the most efficient route. This way each port on a switch can operate at full bandwidth speed.

Hub:

Hubs are like switches in that they connect to other devices on a network using ethernet cables. However instead of directing the data packet to a specific port it sends the data packet to all the ports. A drawback of this is that hubs can only receive or send data at one given time, they also share the total bandwidth between all ports meaning when data is transferring it will cause the network to slow down.