Classifying computer networks by scale refers to categorizing networks based on size or geographical coverage. This classification helps understand the scope and extent of a network and the technologies and infrastructure required to build and maintain it. By considering the scale of a network, we can better understand its capabilities, limitations, and the types of applications it can support.
The scale classification of computer networks typically includes categories such as Personal Area Networks (PAN), Local Area Networks (LAN), Metropolitan Area Networks (MAN), Wide Area Networks (WAN), Campus Area Networks (CAN), and Global Area Networks (GAN). Each category represents a different network scale, ranging from small, localized networks to large-scale networks that span vast geographical areas.
By classifying networks based on scale, network administrators, designers, and engineers can make informed decisions regarding network design, hardware and software requirements, connectivity options, security measures, and overall network management strategies. It helps understand the unique challenges and considerations associated with networks of different scales and enables the appropriate selection and implementation of networking technologies to meet specific requirements.
Now that we know the meaning of classifying computer networks by scale, we will see each network type’s description, history, and more details.
Personal Area Network (PAN)
A PAN is the smallest type of network, typically used for connecting devices within a short range, such as within a person’s workspace or home. Bluetooth and USB connections are examples of PAN technologies.
Local Area Network (LAN)
LANs are used to connect devices within a limited geographical area, such as a home, office building, or campus. LANs often use Ethernet cables or Wi-Fi to connect computers, printers, servers, and other devices.
History of LAN
Below is the history of events for LAN starting from its early days.
- Early LAN Experiments: In the 1960s, researchers began experimenting with computer networks within limited areas. One notable example is the ALOHAnet, a radio-based network developed in Hawaii in 1970, which allowed multiple computers to communicate with a central host.
- Ethernet and Xerox PARC: In the early 1970s, Ethernet, a widely used LAN technology, was invented at Xerox’s Palo Alto Research Center (PARC). Robert Metcalfe and his team developed the Ethernet standard, which allowed multiple computers to share a common coaxial cable.
- Local Area Network (LAN) Definition: The term “Local Area Network” was first coined in the 1970s to describe a network connecting computers within a limited area, typically a building or a campus.
- LAN Standards and Commercialization: In the late 1970s and early 1980s, various LAN standards emerged, including Ethernet, Token Ring, and ARCNET. These standards provided network connectivity and data transmission guidelines, making LANs more accessible and commercially viable.
- LAN Technologies Evolve: Throughout the 1980s and 1990s, LAN technologies continued to evolve. Ethernet gained widespread popularity, and advancements such as twisted-pair cabling, hubs, and switches improved network performance and scalability.
- LAN Interoperability: The Institute of Electrical and Electronics Engineers (IEEE) played a crucial role in standardizing LAN technologies. The IEEE 802 project developed a suite of LAN standards, including IEEE 802.3 (Ethernet) and IEEE 802.5 (Token Ring), ensuring interoperability between different vendors’ equipment.
- LAN Expansion and Integration: Organizations began connecting multiple LANs to create larger networks as LANs became more prevalent. This led to the development of Metropolitan Area Networks (MANs) and Wide Area Networks (WANs) to enable communication between geographically dispersed locations.
- High-Speed LANs and Wireless LANs: In the 1990s and early 2000s, LAN technologies continued to advance, with the introduction of Fast Ethernet, Gigabit Ethernet, and later 10 Gigabit Ethernet, enabling faster data transmission within LANs. Wireless LANs (WLANs) also gained popularity, allowing for flexible and mobile connectivity.
- LAN Virtualization and Convergence: In recent years, virtualization technologies and software-defined networking (SDN) have enabled the virtualization of LANs, making network management more flexible and efficient. Furthermore, LANs have converged with other technologies, such as voice and video communication, leading to the integration of LANs with Voice over IP (VoIP) and video conferencing systems.
Metropolitan Area Network (MAN)
A MAN covers a larger area than a LAN and typically spans a city or a metropolitan region. It may interconnect multiple LANs to provide connectivity to a broader geographic area.
Wide Area Network (WAN)
WANs are designed to connect geographically dispersed networks over long distances, such as connecting branch offices of a company in different cities or even countries. To establish connectivity, WANs utilize technologies like leased lines, MPLS (Multiprotocol Label Switching), or the Internet.
How is WAN different from MAN?
Wide Area Networks (WANs) and Metropolitan Area Networks (MANs) are both network architectures used to interconnect multiple networks, but they differ in several key aspects:
- Geographical Coverage: The primary distinction between WANs and MANs is their geographical coverage. WANs span large geographical areas, often spanning regions, countries, or even continents, and are designed to connect geographically dispersed locations. In contrast, MANs cover a more limited geographic area, typically a metropolitan region or city.
- Distance: WANs cover long distances, allowing connectivity between locations far apart. They utilize various technologies, such as leased lines, satellite links, or internet connections, to establish connections over extended distances. Conversely, MANs cover shorter distances within a metropolitan area, typically within tens of kilometers.
- Network Complexity: WANs tend to be more complex due to the challenges of long-distance communication, which often involve multiple service providers, diverse technologies, and different networking protocols. MANs, by comparison, are generally less complex, as they focus on interconnecting networks within a specific metropolitan area, typically within a single service provider’s infrastructure.
- Connectivity Speed: WANs may offer lower bandwidth and higher latency due to the longer distances and diverse network infrastructure involved. In contrast, MANs often provide higher bandwidth and lower latency due to the shorter distances involved and the availability of high-speed fiber optic connections within a metropolitan area.
- Service Providers: WANs often involve multiple service providers cooperating to establish connectivity between regions. MANs are typically managed and provided by a single service provider that covers the entire metropolitan area.
- Cost: WANs are generally more expensive to implement and maintain due to the long-distance connections, infrastructure requirements, and higher complexity. MANs, being confined to a specific metropolitan area, can be more cost effective to establish and manage.
While WANs and MANs have distinct characteristics, it’s important to note that the boundaries between the two can sometimes be blurred, especially as technology advances. In some cases, the same network infrastructure may serve as both a MAN and a WAN, depending on the specific use and perspective. The categorization of a network as either a WAN or a MAN ultimately depends on the network deployment’s scale, coverage, and connectivity requirements.
History of WAN
The history of Wide Area Networks (WANs) can be traced back to the mid-20th century when the need for connecting geographically dispersed networks and sharing resources emerged. Here’s a brief overview of the key developments in the history of WANs:
- Early Data Communication Networks: In the 1950s and 1960s, early data communication networks were developed to connect mainframe computers within organizations. These networks used dedicated leased lines or modems to establish point-to-point connections over long distances.
- Packet Switching and ARPANET: In the late 1960s, the Advanced Research Projects Agency (ARPA) in the United States introduced the concept of packet switching. This led to the creation of ARPANET, which was the precursor to the modern Internet. ARPANET connected various research institutions and universities, marking the birth of wide-area networking.
- X.25 and Circuit-Switched Networks: In the 1970s and 1980s, the X.25 protocol became popular for WAN connectivity. X.25 allowed for efficient data transmission over circuit-switched networks, enabling connections between geographically distant locations.
- TCP/IP and the Internet: In the late 1970s and early 1980s, the Transmission Control Protocol/Internet Protocol (TCP/IP) was developed as a standardized protocol suite for wide-area networking. TCP/IP facilitated the interconnection of networks, leading to the formation of the Internet as a global WAN.
- Leased Lines and Frame Relay: In the 1980s and 1990s, leased lines were common for establishing WAN connectivity. Leased lines provided dedicated, point-to-point connections between locations. Frame Relay, a packet-switching technology, gained popularity as a more cost-effective alternative to leased lines.
- Asynchronous Transfer Mode (ATM): In the 1990s, ATM emerged as a WAN technology, offering high-speed data transfer and supporting various types of traffic, including voice, data, and video. However, its adoption was limited due to the emergence of newer technologies.
- MPLS and VPNs: Multiprotocol Label Switching (MPLS) gained prominence in the late 1990s and early 2000s as a WAN technology. MPLS allowed for the creation of virtual private networks (VPNs) over shared networks, providing secure and scalable connectivity for businesses.
- Broadband and Internet-based WANs: With the widespread availability of broadband internet access, WAN connectivity shifted towards using Internet-based technologies. Virtual Private Network (VPN) solutions based on Internet Protocol Security (IPsec) and Secure Socket Layer (SSL) gained popularity, allowing secure and cost-effective WAN connectivity.
- Software-Defined WAN (SD-WAN): In recent years, Software-Defined WAN (SD-WAN) has emerged as a technology that simplifies the management and operation of WANs. SD-WAN offers centralized control, increased flexibility, and improved performance through dynamic traffic routing and efficient utilization of multiple WAN links.
The history of WANs has been characterized by advancements in networking protocols, the development of new technologies, and the ever-increasing demand for connecting geographically dispersed locations. WANs continue to evolve, enabling businesses to connect offices, branches, and remote locations, supporting a wide range of applications and services across the globe.
Campus Area Network (CAN)
A CAN is a network that covers a specific geographical area, typically a university campus or a corporate campus. It connects multiple LANs and provides high-speed communication between various buildings or departments within the campus.
Global Area Network (GAN)
A GAN refers to a network infrastructure that spans the entire globe. It connects different networks and facilitates communication between widely distributed locations. The Internet is the most well-known example of a GAN.
Now that you have gone through detailed descriptions of each network type let us see some real-life examples.
Real-Life Examples to make the concepts clear
Here are some real-life examples of different network types in daily life. This will make the concepts clearer as you can relate to these examples easily.
Personal Area Network (PAN):
- Bluetooth: PANs are commonly used with Bluetooth technology to connect personal devices such as smartphones, tablets, and wearable devices to each other or to peripherals like wireless headphones or smartwatches.
Local Area Network (LAN):
- Home Network: Most homes have a LAN to connect devices such as computers, laptops, printers, and smart TVs to a central router, allowing them to share files, access the internet, and communicate with each other.
- Office Network: LANs are extensively used in offices and workplaces to interconnect computers, servers, printers, and other devices within a building or a floor.
Metropolitan Area Network (MAN):
- City-wide Wi-Fi: Some cities provide free or paid Wi-Fi services covering a large portion of the urban area. These Wi-Fi networks serve as a MAN, enabling residents and visitors to access the internet while on the move within the city.
Wide Area Network (WAN):
- Internet: The internet itself is a prime example of a global-scale WAN. It connects networks and devices worldwide, enabling communication, access to information, and various online services.
- Corporate WAN: Large organizations with multiple branches or offices often establish WANs to interconnect their geographically dispersed locations. These WANs allow centralized management, data sharing, and seamless communication between sites.
Campus Area Network (CAN):
- University Campus Network: Universities and educational institutions typically have CANs that span their entire campus. These networks provide connectivity to various academic buildings, student dormitories, research facilities, and administrative offices.
Global Area Network (GAN):
- Cellular Networks: GANs are exemplified by global cellular networks operated by telecommunication companies. These networks connect mobile devices worldwide, enabling voice calls, messaging, and internet access through cellular data services.
It’s important to note that these examples showcase the general use cases for each network type, but the specific implementations and technologies can vary. Additionally, technological advancements continually expand the possibilities and reach of different network types.
To know how you can classify computer networks based on technology used for transmission, refer to this article – Network Hardware: Classification based on Transmission Technology.