Understanding Network Basics: Components, Types, and Topologies
When it comes to the world of technology, computer networks are the backbone that connects us all. But what exactly do we mean when we talk about computer networks? Is it limited to just computers? And is it confined to technologies like Ethernet, WiFi, or fiber optics? In this article, we’ll dive into the basics of networks, covering everything from their purpose to key components and network types.
Overview of Networks
Purpose of Networks
At its core, the purpose of a network is to establish connections between machines. Whether it’s your laptop accessing the internet, a smartphone connecting to a Wi-Fi hotspot, or servers facilitating data transfer, networks are the highways that make it all possible. Converged networks are capable of handling various types of traffic, including data, video, and voice. The expectation is high, with network reliability targets often set at 99.999% availability, colloquially known as “The 5 9’s,” allowing for only 5 minutes of downtime per year.
Network Traffic Examples
Networks facilitate a wide range of activities, including file sharing, video chatting, web browsing, social media interactions, streaming video, emailing, messaging, and even Voice over IP (VoIP) communication.
A client is any device an end-user uses to access the network. This can be a workstation, laptop, tablet, smartphone, television, server, or any other terminal device capable of connecting to the network.
Servers provide resources to the network, and they come in various types, such as E-mail servers, Web servers, File servers, Chat servers, and Print servers. Servers can be dedicated hardware or software, or they can be devices serving specific functions.
Hubs are older network technologies used to connect networked devices like clients and servers. They can be interconnected to provide additional ports, but this can lead to increased network errors. Hubs receive information on one port and rebroadcast it to all other ports.
Wireless Access Point (WAP)
WAPs enable wireless devices to connect to wired networks. They are commonly used in homes, small businesses, and even large enterprise networks. Essentially, a WAP acts as a wireless hub.
Switches connect networked devices like clients and servers (similar to hubs). However, switches learn which devices are connected to which switch ports, allowing for more efficient traffic routing based on device MAC addresses. This enhances security and optimizes available bandwidth.
Routers connect different networks together and intelligently forward traffic based on logical addresses. Most modern routers use Internet Protocol (IP) addresses to determine how traffic should be routed.
Networks rely on various media types to connect devices. These include copper cables, fiber optic cables, and radio frequency waves (WiFi). Each media type has its strengths, limitations, bandwidth, capacity, distance coverage, and installation costs.
Wide Area Network (WAN) Link
WAN links physically connect networks and can be established through leased lines, DSL, cable, fiber optic, satellite, cellular, microwave, and more. They connect internal networks to external networks, such as linking a small office/home office (SOHO) network to the internet.
In the client/server model, dedicated servers provide access to resources like files, scanners, and printers. Administration and backup are more straightforward since resources are concentrated on a few key servers.
Benefits of Client/Server
- Centralized administration
- Easier management
- Better scalability
Drawbacks of Client/Server
- Higher cost
- Requires dedicated resources
- Needs a network operating system
In peer-to-peer networks, peers (PCs) directly share resources like files and printers. Administration and backup are more challenging since resources are distributed across multiple PCs.
Benefits of Peer-to-Peer
- Lower cost
- No dedicated resources required
- No specialized operating system required
Drawbacks of Peer-to-Peer
- Decentralized management
- Inefficient for large networks
- Limited scalability
Personal Area Network (PAN)
PANs are the smallest type of wired or wireless networks, covering only a few meters. Examples include connecting a Bluetooth cellphone to a car, a USB hard drive to a laptop, or a Firewire video camera to a computer.
Local Area Network (LAN)
LANs connect components within a limited distance, typically up to 100 meters with CAT 5 cabling. They consist of Ethernet (IEEE 802.3) or WiFi networks (IEEE 802.11) and are commonly used for internal wired or wireless networks.
Campus Area Network (CAN)
CANs link LANs within a university, industrial park, or business park, covering many square miles and buildings. Examples include college campuses, business parks, and military bases.
Metropolitan Area Network (MAN)
MANs connect scattered locations across a city and cover up to a 25-mile radius in larger cities. Examples include city departments like the police department or community colleges with campuses spread across a county.
Wide Area Network (WAN)
WANs connect geographically distant internal networks and consist of leased lines or Virtual Private Networks (VPNs) tunne.