Networks | Part 2 of 3
In Part 1 we talked about large networks which we call WANs and looked into basic Internet technologies. Now we will transition into smaller networks that are usually confined to a single building like our home network or at school or at work.
Local Area Network aka LAN
A Local Area Network, or LAN in short, is a computer network that spans a relatively small area. In fact, most LANs are confined to a single building for example, a home network or a school network which is configured and maintained by our IT technician. Individual LANs are the building blocks of larger networks that could cover large distances, and as we suggested in Part 1 a complex system of interconnected LANs all over the world makes up the WAN.
Your Teacher's Home LAN
Many of our devices at home seem to work with an internet connection these days. My home LAN looks something like the following diagram, does it look similar to your home network?
Wired and Wireless Connection
My home LAN has wired and wireless connections. Devices on a network need a physical medium to transmit data and we have two main options here: we can install physical cables, for example an ethernet cable, or use something invisible like radio waves.
Taking a look at the example above, my router, my modem, my TV box, my desktop computer, and my printer all make use of a wired connection. You probably know that there are different wiring options. People normally recommend a strong coaxial cable or if possible a fiber optic cable for the TV and the modem/router. The printer and home office desktop only need a simple twisted pair ethernet cable.
My game console, my portable devices, and my air conditioner all use Wi-Fi to connect to the internet. Wi-Fi is a networking technology that uses radio waves to allow high-speed data transfer over short distances. We need specialised networking hardware like access points to transmit and receive radio frequency signals to and from our wireless devices; nowadays our wireless routers have this ability so we do not think much of it. Wireless connectivity is convenient and it is quite easy to add a device to a WLAN, where w simply stands for wireless.
You might think that the airconditioner and the smart bulb seem a bit out of place since they are not conventional computers that need to make use of network resources, like the printer.
These network of small devices and appliances with sensors are often referred as Internet of Things (IoT) because they connect to the internet to exchange small bits of data and be controlled by a mobile app. Some common IoT devices also include smart thermostats, smart fridges and security cameras.
Wired vs Wireless Connections
Wired | Wireless |
Our School LAN
We can easily collabore, share files, and administer our computer labs because the school as setup a Local Area Network (LAN) environment, providing several benefits. You will probably relate to the following:
Sharing Secondary Storage The shared Z: drive, hosted on the school server, acts as central storage for our installation files and your schoolwork. We also use it to facilitate file sharing making group work easier.
Shared Internet Access All computers on the LAN can share a single internet connection via ethernet cables allowing you to access online resources during lessons, like the notes you are reading now! Ethernet cables to give you reliable and secure internet connection.
Shared Policies Our network administrator enforces consistent policies across all connected computers, ensuring security protocols, software updates, and configurations are applied uniformly.
Our school network is probably too large and complex to depict it accurately in a diagram. The image below illustrates the basics.
Monitoring Network Activity
From the server, the network administrator can monitor all the computers that are connected to the school network. But, how can he uniquely identify every single computer in the lab? Well, you might suggest that he uses the IP address since our computers are connected to the internet anyway. However, in a school environment, it is very likely that the IP addresses change every time he reboots the network.
So what can he do? Well, he can use the MAC address to keep track of the devices. MAC stands for Media Access Control Address an address tied to the physical hardware. Every device that can connect to a network is equipped with a Network Interface Controller (NIC), or more commonly known as ethernet card or Wi-Fi card, and the MAC address is manufactured into it. MAC addresses are made up of hexadecimal numbers separated by colons e.g., 00:0d:83:b1:c0:8e. Since it is provided by the manfacturer it is impossible to change it.
To ensure that communication travels from the server to the right computers and vice versa we use the mysterious black box under the whiteboard which is called a switch. A switch is a networking device that sends the data to the intended computer, by using its MAC address. Like this, we can group devices in close proximity, to reduce network congestion and make communication more efficient.
Network Safety Means Your Safety
It is important for us that you can use the computers, and the internet during lessons safely. The network administrator configures a firewall to protect the network, the data, and of course you, the student.
A firewall is a network device or a piece of software that analyzes traffic entering and leaving a protected network. It will refer to a list of rules to either "allow" or "block" activity both in and out of the network. Therefore, network activity which cannot be trusted will not be allowed to enter.
The installation and configuration of a firewall can protect data on a network from unauthorized access by hackers who tend to use a variety of tools that can quickly harm a network like a virus.
A Work LAN
The LAN is a common setup at the workplace to facilitate communication between employees, teamwork, and data management. You might be thinking that a work LAN should not be too different from our school LAN, and you are absolutely right. A work LAN can share all the characteristics we mentioned already.
Benefits A centralized server allows for secure storage that can be accessed by personnel eanbling the sharing of files, and resources e.g., printers in the same office space. The computers at the office all share internet access which improves communication and collaboration.
Risks Depending on the size of the network, and the operational day-to-day of the company, high usage can lead to network congestion. Data privacy, and keeping the network safe is really important so the implementation of security measures e.g., firewall or encryption is required.
Networking Hardware Switches are used to connect devices within the LAN, ensuring data is transmitted only to the intended recipient.
Teamwork Environment
In a modern working space, people work together, and people work with different people. While it is common for personnel to have their designated desk, they are expected to move freely within the company and collaborate with the right people. Wireless devices, e.g., laptops can enable "hot-desking" arrangements. This means that while a person is on his desk, the laptop hooks up to a docking station that has direct power and a secure and reliable wired connection to the network and the internet. When a person is not working at their designated desk, then wireless connectivity to the network and internet is needed. Access Points (AP) are devices that allow wireless devices to connect to a wired LAN. Employees can move around the office while maintaining network connectivity, promoting collaboration and productivity.
File Sharing with File Transfer Protocol
The File Transfer Protocol (FTP) is commonly used in workplaces to facilitate the transfer of files between computers on the LAN and external servers. Employees can upload and download files securely and efficiently using programs like FileZilla. Employees may may need to collaborate on projects and perhaps avoid transferring the very large files via the internet, or simply backup important data on their laptop on to the server.
Working from Home using VPN
With an increasing number of employees working remotely, Virtual Private Networks (VPN) have become essential for secure access to the office LAN from another location that is connected to the internet. This type of network has important advantages:
Encrypted Connection A VPN establishes a secure, encrypted connection over the internet, allowing employees to access resources on the LAN as if they were physically present in the office.
Data Privacy It ensures data privacy and security, especially when connecting to sensitive company systems or handling confidential information.
Conclusion
We understand that this might be a long post, but this structure should help you understand why we need different types of networks e.g., WAN and LAN for various scenarios. By looking at three different scenarios we explored the benefits, hardware components, and applications of LANs. Whether it is for sharing a printer at home, or learn at school, or work from home, it is important to choose the right configuration. Understanding different configurations will enable you to justify the use of a specific network for a given scenario.
Quiz
Which device would I use if I had 5 computers but only had 3 ports available on my router? Use a Switch to connect some computers, and run a single wire from the Switch to one port on the router.
What type of transmission does Wireless LAN use? Microwave transmission.
What are some examples of home devices (shared resources) that could be used by multiple computers/devices on the networks? Printers, scanners, media centres and network drives.
If my computer is connected to my home WIFI but getting a very weak connection. What can I do to my network to improve this? Either connect the computer using a wire to a switch if one is close, or install a repeater to boost the wireless signal to and from the router.
What are some advantages of using a wireless connection over a wired connection? Wireless connections provide more flexibility and mobility since you can connect to the network from anywhere within range. They also don't require any physical cables, which can make them easier to set up and use.
What are some examples of IoT devices? Some examples of IoT devices include smart home devices (such as thermostats and door locks), wearable devices (such as fitness trackers and smartwatches), and industrial devices (such as sensors and controllers used in manufacturing and agriculture).
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