Successful network installation is about more than just the cables. These are the devices that are essential to building a physical and digital network infrastructure:
- Hub
- Switch
- Router
- Modem
- Firewall
- Server
Each of these devices has different functions within the network that complement each other for maximum network efficacy and efficiency. Understanding the role of these devices will give you a better grasp of how a network actually functions, and how important comprehensive installation and configuration practices are.
What is a Hub?
A hub is the simplest device on a network, but also very central to its operation. As the name implies, a hub links multiple devices. It does this by funneling data packets and/or signals to all its connected devices.
A hub can transmit digital and analog data, but it needs to be properly configured in order to do so. It also amplifies signals that deteriorate after traveling through long cable runs in a function known as repeating.
A hub does not interfere with, filter, or address data packets or signals that it transmits. That’s the job of the network switch.
What is a Switch?
A network switch connects devices within a network and forwards data packets between them. Switches increase network efficiency by using routing information to read the hardware address of an incoming packet or signal and send it to the correct device.
The physical form of the network switch is generally also “multiport,” which allows multiple devices to be linked onto the network. Sometimes in network installation design, multiple switches are used to create multiple sub-networks of devices and equipment for greater overall network organization.
A switch is more intelligent than a hub in directing traffic, but not as intelligent as a router and has limited configuration options. And unlike a network router, which can accept and interpret packets from outside of the network, switches concern themselves solely with intra-network packets.
What is a Router?
A router determines a data packet’s best route through the network to reach its destination. Routers maintain a list of known network addresses, and have protocols to direct data packets when the address is not known.
The router stores information about the network in a data set known as a routing table, which grows dynamically as the network exchanges information. Here’s how it works: when the router receives a packet, the router analyzes it to determine its data type, source address, and destination address. This information is logged and new addresses are added to the routing table, and helps the router learn which routes on the network are most reliable for packets to travel through.
Network topology plays a role in how routers direct data, as the routes available to a packet depend on both the physical and the digital layout of the network. Routers have the ability to break large packets of data down into smaller packets if the framework of the network requires it. They can also forward data from one network to another.
Routers are separate from firewalls but are just as important to overall network security, as they can be configured to only allow traffic that is approved by system administrators. And while they can forward data from one network to another and split Internet access across multiple devices, routers by themselves can’t access the Internet unless hooked up to a network modem.
What is a Modem?
“Modem” is an abbreviation for “modulators-demodulator”. A modem allows your computer or network to send and receive data over the internet–which is why rebooting a modem often addresses Internet connectivity problems. It essentially acts as a gatekeeper for a network’s internet access.
The modem receives an analog signal from an Internet Service Provider over analog network cables–either phone lines (old-school DSL), Cat-type cable, or fiber optic cables–and then converts it into digital signals that computers can receive and understand. It also performs the same process in reverse when a computer goes to send data over the Internet.
While a modem is necessary for internet access, a router and switch are necessary to convey that access to multiple devices on the network. Modems also do not have significant built-in security features, which brings us to the network firewall.
What is a Firewall?
Network firewalls are devices that act as a secure buffer between the inside the network and the outside the network. They use special protocols to police all incoming and outgoing network traffic, communications, and transactions, to make sure that malware, viruses, worms, hackers, and other security threats remain outside. They also prevent unauthorized access to the network by other devices or users.
Firewalls are not the only security measure you should employ on a network, but they are nonetheless essential to overall network security. A firewall on a computer protects only the data and applications on that computer, but a network firewall protects all the devices on the network from malicious attacks–including the very important network server.
What is a Network Server?
Network servers act as a shared central point for all devices on a server. Servers share, store, and maintain data and files that can be accessed in real time by devices across the network.
Network servers keep this shared data safe by keeping it stored on a secure hard drive with regular backups, and because access is shared, they facilitate collaboration between different users.
These servers also:
- Host multi-user applications, such an email client or proprietary software
- Connect computers to shared devices like scanners or printers
- Centralize resources for easy research and utilization
- Control access to these resources through the use of network log-in and connections
For businesses that deal with especially data-heavy applications such as graphic design or CAD programs, a dedicated file server provides additional memory space and network stability.
