Switches are devices used in connecting a Local Area Network, otherwise known as a LAN. A home network consisting of two computers that share an Internet connection and possibly a printer is a good example of a simple LAN that might employ an unmanaged switch. As the number of computers connected to a network increases, the complexity of that network will eventually reach a point where monitoring and control become imperative. To address that need, managed switches can be deployed, allowing the network administrator access to the necessary tools to regulate the network.
A LAN consists of computer and peripheral devices that communicate by sending small pieces of data called packets to each other. Packets are data agnostic and can consist of any kind of data from word processing documents attached in an email to an IP-based camera sending a video stream or even a VoIP telephone conversation.
All packets are not equal in their priority; when each packet is delivered will make a difference in the quality of the application being run. Specifically, the packets that make up part of a VoIP conversation are acutely time sensitive, whereas the packets that make up an email and attachment will remain unaffected if they are delayed for a second. In small networks, the amount of data that gets sent at any given time will remain minimal as compared to a large office, where dozens of computers are all sending and receiving data simultaneously. In order to ensure that data is prioritized according to its need, management is necessary to ensure that the time-sensitive packets are delivered as quickly as possible.
In scenarios where the network traffic is light, all that is required is a way for the data to pass from one device to another. In this case there is no need for prioritizing the packets, as all the traffic will flow unimpeded. An unmanaged switch will fill this need without issues. It is important to note that a switch is not a hub. Hubs were a predecessor to switches and provide a similar but less-capable function.
As the number of devices increases, the ability to ensure that the time-sensitive packets are prioritized becomes increasingly difficult as more concurrent streams of data hit the network. Another issue that may need to be dealt with is which devices have access to what portion of the network. An example of this might be where the accounting department needs to be walled off from the rest of the network for security purposes or where the production floor should be blocked from having Internet access. In both those cases a managed switch can fulfill that need. In addition, managed switches provide the ability to monitor each device on the network as well as limit the amount of bandwidth any device can use.
Another class of switches is the Smart Switch, which offers some of the capabilities that managed switches offer but are more limited and less expensive that a managed switch. Smart Switches can make an excellent transition solution when the cost of a managed switch cannot be justified.