Networks: What You Need to Know - YSTN

 Have you ever wondered how your computer connects to the internet, or how your smartphone can send messages to your friends? If so, then you have been curious about networks. Networks are systems of devices that can communicate and share information with each other. Networks are everywhere in our modern world, from our homes and offices to our schools and hospitals. Networks enable us to access online services, collaborate with others, and enjoy various forms of entertainment.

But what exactly are networks, and how do they work? What are the different types of networks, and what are their advantages and disadvantages? In this article, we will answer these questions and more. We will explain the basic concepts of networks, such as network topology, network devices, and network protocols. We will also explore the most common network types, such as LAN, WAN, MAN, PAN, and VPN. By the end of this article, you will have a better understanding of networks and their use cases.

What is a Network?

A network is a group of two or more devices or nodes that can communicate with each other. The devices or nodes in question can be connected by physical or wireless connections. The key is that there are at least two separate components, and they are connected.

The purpose of a network is to enable the exchange of data and resources among the devices or nodes. Data can be anything from text and images to audio and video. Resources can be anything from printers and scanners to servers and databases. By sharing data and resources, networks can improve efficiency, productivity, and security.

There are many ways to classify networks based on different criteria, such as size, connectivity, coverage, and design. In this article, we will focus on the most common network types based on size: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and virtual private network (VPN).

Personal Area Network (PAN)

A personal area network (PAN) is the smallest and simplest type of network. PANs connect devices within the range of an individual and are no larger than about 10 meters (m). Because PANs operate in such limited areas of space, most are wireless and provide short-range connectivity with infrared technology or Bluetooth.

An example of a wireless PAN is when users connect Bluetooth devices, such as wireless headsets or smartwatches, to a smartphone or laptop. Although most PANs are wireless, wired PAN options exist, such as USB.

Advantages of PAN

• Portability: Most devices that connect in a PAN are small and can be easily transported.
• Affordability: The ability to form a connection between two devices in a PAN without additional wiring is generally less expensive compared to a wired network.
• Reliability: PANs guarantee stable connectivity between devices, provided that the devices remain within the 10 m range.
• Security: PANs don’t directly connect to larger networks, but rather to other devices connected to larger networks. The security of a device in a PAN is contingent upon how secure the intermediary device is within the larger overall network.

Disadvantages of PAN

• Limited range: PANs can only cover a small area of space, which limits their functionality for larger purposes.
• Interference: PANs can be affected by interference from other wireless signals or physical obstacles that may disrupt the connection.
• Compatibility: Not all devices support the same wireless technologies or protocols that enable PANs. For example, some devices may not have Bluetooth capabilities or may use different versions of Bluetooth.

Use Cases of PAN

PANs are configured so individual users can connect their devices within their personal vicinity. A literal example of this is a body area network (BAN), in which a user physically wears connected devices such as fitness trackers or health monitors. Small home networks with computers, printers, and other wireless devices are also considered PANs. Looking ahead, PANs could function as a key player in the world of IoT systems in both offices and homes.

Local Area Network (LAN)

A local area network (LAN) is a system where computers and other devices connect to each other in one location. While PANs connect devices around an individual, the scope of a LAN can range from a few meters in a home to hundreds of meters in a large company office.

The network topology determines how devices in LANs interconnect. There are different types of network topologies, such as bus, star, ring, mesh, tree, and hybrid. Each topology has its own advantages and disadvantages depending on the size and complexity of the LAN.

Information sharing and communication between devices over different topologies is possible with Wi-Fi or Ethernet cables. Wi-Fi uses radio waves to transmit data wirelessly, while Ethernet uses twisted pair cables to transmit data electrically.

Advantages of LAN

• Speed: LANs can provide fast data transfer rates, up to 10 Gbps with Ethernet cables and up to 1 Gbps with Wi-Fi.
• Cost: LANs can be relatively cheap to set up and maintain, as they require less hardware and cabling than larger networks.
• Security: LANs can be secured with passwords, firewalls, encryption, and other methods to prevent unauthorized access or data breaches.
• Resource sharing: LANs enable users to share devices such as printers, scanners, or storage drives, as well as software applications and files.

Disadvantages of LAN

• Limited coverage: LANs can only cover a small geographic area, which limits their functionality for larger purposes.
• Scalability: LANs can become difficult to manage and expand as the number of devices and users increases.
• Dependency: LANs rely on a central server or device to function properly. If the server or device fails, the whole network may be affected.
• Congestion: LANs can experience network congestion or slowdowns when too many devices or users are accessing the network at the same time.

Use Cases of LAN

LANs are widely used in various settings, such as homes, schools, offices, libraries, and hotels. LANs enable users to access online services, collaborate with others, and enjoy various forms of entertainment. For example, a home LAN may allow users to stream movies from a media server to a smart TV, or play online games with other users on the same network. A school LAN may allow students and teachers to access educational resources, submit assignments, and communicate via email or chat.

Metropolitan Area Network (MAN)

A metropolitan area network (MAN) is a system that connects multiple LANs within a larger geographic area, such as a city or a town. A MAN can span up to 50 kilometers (km) and can serve thousands of users. A MAN is typically owned and operated by a single entity, such as a government agency, a corporation, or an internet service provider (ISP).

A MAN can use various technologies and protocols to interconnect LANs, such as fiber optic cables, microwave links, or WiMAX. Fiber optic cables use light pulses to transmit data over long distances with high speed and low interference. Microwave links use electromagnetic waves to transmit data wirelessly over line-of-sight paths. WiMAX is a wireless technology that provides broadband internet access over large areas.

Advantages of MAN

• Coverage: MANs can cover a large geographic area, which enables them to provide internet access and other services to many users and locations.
• Speed: MANs can provide high-speed data transfer rates, up to 10 Gbps with fiber optic cables and up to 70 Mbps with WiMAX.
• Cost: MANs can be cost-effective for entities that need to connect multiple LANs within a city or a town, as they eliminate the need for long-distance communication lines or multiple ISPs.
• Performance: MANs can provide better performance and reliability than WANs, as they have less latency and congestion.

Disadvantages of MAN

Complexity: MANs can be complex to set up and maintain, as they require specialized equipment and expertise.

Security: MANs can be vulnerable to security threats such as hacking, eavesdropping, or sabotage, as they involve multiple networks and devices that may have different security standards or protocols.

Regulation: MANs can be subject to legal and regulatory issues such as licensing, taxation, or censorship, depending on the location and the entity that owns and operates the network.

Use Cases of MAN

MANs are mainly used by entities that need to provide internet access and other services to multiple locations within a city or a town. For example, a government agency may use a MAN to connect its offices and facilities across the city. A corporation may use a MAN to connect its headquarters and branches within the same metropolitan area. An ISP may use a MAN to provide broadband internet access to its customers in different neighborhoods.

Wide Area Network (WAN)

A wide area network (WAN) is a system that connects multiple LANs or MANs across large geographic distances, such as countries or continents. A WAN can span hundreds or thousands of kilometers and can serve millions of users. A WAN is typically owned and operated by multiple entities, such as governments, corporations, or ISPs.

A WAN can use various technologies and protocols to interconnect LANs or MANs, such as satellite links, cellular networks, or VPNs. Satellite links use artificial satellites orbiting the earth to transmit data wirelessly over long distances. Cellular networks use cell towers and mobile devices to transmit data wirelessly over short distances. VPNs are virtual networks that use encryption and tunneling techniques to create secure connections over public networks such as the internet.

Advantages of WAN

• Coverage: WANs can cover vast geographic areas, which enables them to provide global connectivity and communication and collaboration across the world. WANs enable users to access online services, collaborate with others, and enjoy various forms of entertainment across different regions or countries.
• Cost: WANs can be cost-effective for entities that need to connect multiple LANs or MANs across large geographic distances, as they can use existing public networks such as the internet or leased lines from ISPs.
• Scalability: WANs can be easily scaled up or down as the number of devices and users changes, as they can use cloud-based services or virtual networks to add or remove resources as needed.
• Performance: WANs can provide better performance and reliability than LANs or MANs, as they can use advanced technologies and protocols such as SD-WAN, MPLS, or VPN to optimize network traffic and ensure quality of service.

Disadvantages of WAN

• Complexity: WANs can be complex to set up and maintain, as they require specialized equipment and expertise.
• Security: WANs can be vulnerable to security threats such as hacking, eavesdropping, or sabotage, as they involve multiple networks and devices that may have different security standards or protocols.
• Regulation: WANs can be subject to legal and regulatory issues such as licensing, taxation, or censorship, depending on the location and the entity that owns and operates the network.

Use Cases of WAN

WANs are mainly used by entities that need to provide global connectivity and collaboration across different locations. For example, a multinational corporation may use a WAN to connect its offices and facilities across the world. A government agency may use a WAN to provide public services and information to its citizens in different regions or countries. An ISP may use a WAN to provide internet access and other services to its customers in different areas.

Virtual Private Network (VPN)

A virtual private network (VPN) is a system that creates a secure connection over a public network such as the internet. A VPN allows users to access network resources remotely without compromising their privacy or security. A VPN works by encrypting the data that travels between the user’s device and the VPN server, making it unreadable by anyone who intercepts it.

A VPN can use various technologies and protocols to create secure connections, such as IPsec, SSL/TLS, PPTP, L2TP, or OpenVPN. Each technology and protocol has its own advantages and disadvantages depending on the level of security, speed, and compatibility required.

Advantages of VPN

• Privacy: VPNs protect the user’s identity and online activity from prying eyes such as ISPs, hackers, or government agencies. VPNs also prevent websites from tracking the user’s location or browsing history.
• Security: VPNs protect the user’s data from cyberattacks such as malware, phishing, or ransomware. VPNs also prevent man-in-the-middle attacks or DNS hijacking that may redirect the user to malicious websites.
• Access: VPNs allow the user to access network resources that may be blocked or restricted by geographic location or network policies. For example, a user can access a website that is censored by their country’s government, or a remote worker can access their company’s intranet from home.

Disadvantages of VPN

• Speed: VPNs can reduce the speed of the user’s internet connection due to encryption overhead and extra network hops. The speed may also vary depending on the distance between the user and the VPN server, the quality of the VPN service provider, and the network congestion.
• Compatibility: VPNs may not work well with some devices or applications that require specific network settings or protocols. For example, some online games or streaming services may not function properly with a VPN connection.
• Reliability: VPNs may not always provide a stable connection due to technical issues such as server downtime, bandwidth limitations, or configuration errors. The reliability may also depend on the quality of the VPN service provider and their customer support.

Use Cases of VPN

VPNs are widely used by individuals and organizations for various purposes. For example, an individual may use a VPN to browse the web anonymously, access geo-restricted content, or bypass network censorship. An organization may use a VPN to enable remote work, secure data transmission, or comply with regulatory requirements.

Network Security

Network security is the field of cybersecurity focused on protecting computer networks from cyber threats. Network security has three chief aims: to prevent unauthorized access to network resources; to detect and stop cyberattacks and security breaches in progress; and to ensure that authorized users have secure access to the network resources they need, when they need them.

As networks grow in size and complexity, so does the risk of cyberattack.  For example, according to IBM’s Cost of a Data Breach 2022 report, 83 percent of organizations surveyed experienced more than one data breach (a security breach that results in unauthorized access to sensitive or confidential information). These attacks were expensive: The global average cost of a data breach is USD 4.35 million, and the average cost of a data breach in the United States is more than twice that amount, USD 9.44 million.

Network security safeguards the integrity of network infrastructure, resources and traffic to thwart these attacks and minimize their financial and operational impact.

Types of Network Security Technologies

Network security systems work at two levels: at the perimeter and inside the network. At the perimeter, security controls try to stop cyberthreats from entering the network. But network attackers sometimes break through, so IT security teams also put controls around the resources inside the network, like laptops and data. Even if attackers get in, they won’t have free reign. This strategy—layering multiple controls between hackers and potential vulnerabilities —is called “defense in depth.”

To build network security systems, security teams combine the following tools:

• A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules. Cisco offers both threat-focused firewalls and unified threat management (UTM) devices.
• An intrusion prevention system (IPS) scans network traffic to actively block attacks. Secure IPS appliances do this by correlating huge amounts of global threat intelligence to not only block malicious activity but also track the progression of suspect files and malware across the network to prevent the spread of outbreaks and reinfection.
• Workload security protects workloads moving across different cloud and hybrid environments. These distributed workloads have larger attack surfaces, which must be secured without affecting the agility of the business.
• NetWORK security is Cisco’s vision for simplifying network, workload, and multicloud security by delivering unified security controls to dynamic environments.
• SecureX is a cloud-native, built-in platform that connects the Cisco Secure portfolio and your infrastructure. It allows you to radically reduce dwell time and human-powered tasks.
• Network segmentation divides a larger network into smaller subnetworks based on criteria such as user identity, location, or device type. This limits the scope of potential attacks and reduces the damage they can cause.
• A virtual private network (VPN) encrypts the connection from an endpoint to a network, often over the internet. A VPN allows users to access network resources remotely without compromising their privacy or security.

Conclusion

Networks are essential for our digital world, as they enable us to communicate, collaborate, and access information across different devices and locations. However, networks also pose challenges and risks that require careful planning and management. In this article, we have learned about the basic concepts of networks, such as network topology, network devices, and network protocols. We have also explored the most common network types based on size: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and virtual private network (VPN). Finally, we have discussed the importance of network security and the technologies that can help us protect our networks from cyber threats.