Network Hardware

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Here we will discuss: Modem, router, cable, Network interface controller, Wireless access point, hub and a switch. You need to understand the purpose of the network hardware but not how they work.

Modem (Modulator-Demodulator):

• A modem connects your home network to the wider internet.
• It modulates digital signals from your ISP into an analog signal that can travel over phone lines (DSL), coaxial cables (cable internet), or fiber optic cables.
• It demodulates incoming analog signals back into digital data that your devices can understand.
• A modem usually provides a single connection to a network, meaning you can connect only one device at a time directly to the internet.
• Most modems will have at least two ports: one that connects to the external service line (like cable or DSL) and one Ethernet port for connecting to a computer or router.

Router:

• A router creates and manages a local area network (LAN).
• It routes data from the internet to the appropriate devices on your home network.
• Routers use IP addresses to make sure that the data sent from the internet reaches the correct device.
• They often include built-in security features like firewalls to protect your network from external threats.
• A router typically provides multiple Ethernet ports for wired connections and Wi-Fi capabilities to connect devices wirelessly.
• Routers can connect to modems via an Ethernet cable to provide internet access to all devices on the LAN.

Combination Modem/Router:

• Many ISPs offer devices that are a combination of both a modem and a router.
• These devices can connect to the internet and also create a LAN, providing both functions in a single piece of equipment.

Differences and How They Work Together:

• The modem is your home’s gateway to the internet, and the router allows multiple devices to connect to that gateway and communicate with the internet and each other.
• Without a modem, your router would have no internet signal to distribute, and without a router, you would only be able to connect one device to the internet at a time.
• The two devices can be separate, or combined into a single unit, but they perform these distinct functions to allow multiple devices in your home to access the internet securely and reliably.

In summary, while a modem connects you to the internet, a router connects your devices to each other and to the modem. For most home networks, both are essential to provide internet access to all devices.

Cables

There are two main methods for connecting devices:

• Wired
• Wireless

With physical, wired connections, we have many cable choices available to us. The three most popular are:

• Twisted pair
• Coaxial
• Fibre optic

Twisted Pair:

• Description: Twisted pair cables consist of pairs of copper wires twisted together. This design helps to reduce electromagnetic interference and crosstalk from adjacent pairs and other electrical sources. Twisted pair cabling is commonly used for telephone communications and local area networks (LANs), with the most familiar example being Ethernet cables.
• Variants: There are two types of twisted pair cables: Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP). UTP is the most common in business and home networks. STP has additional shielding to provide extra protection against interference.
• Speed and Distance: The performance can range from 10 Mbps (Cat 3) up to 10 Gbps (Cat 6a and above), with the effective operational distance decreasing as speed increases.

Coaxial:

• Description: Coaxial cable, or coax, has a single copper conductor at its core, with a plastic layer providing insulation between the center conductor and a metal shield. The shield helps to block out interference from external sources. Coaxial cables are widely used for cable television systems, internet, and other data communications.
• Speed and Distance: Coaxial can carry signals at higher frequencies than twisted pair cables, offering broadband internet access over a single cable. Speeds can vary greatly depending on the technology used, with some modern implementations supporting gigabit speeds.

Fibre Optic:

• Description: Fibre optic cables use thin strands of glass or plastic fibers to transmit data as pulses of light. This technology is known for its high-speed data transmission and resistance to electromagnetic interference. Fiber optic cables are ideal for long-distance communication and are central to modern telecommunications systems.
• Speed and Distance: Fibre optic cables can support incredibly high speeds, with some networks supporting speeds of 100 Gbps or more. They are also capable of maintaining high speeds over much longer distances than either twisted pair or coaxial cables, often up to 40 kilometers without needing signal regeneration.

Comparison:

• Interference: Twisted pair cables, especially UTP, are more susceptible to electromagnetic interference compared to coaxial cables and fiber optic cables. Fiber optic cables are the most immune to interference because they use light to transmit data, which is not affected by electromagnetic interference.
• Installation and Maintenance: Twisted pair cables are generally easier and less expensive to install and maintain than coaxial or fiber optic cables. However, they are more vulnerable to physical damage. Coaxial cables are durable and have better shielding, which makes them less prone to damage and interference but more difficult to handle due to their stiffness. Fiber optic cables require more care in installation due to the fragility of the glass or plastic fibers but are the most future-proof option, offering higher speeds and better signal quality over long distances.
• Bandwidth and Speed: Fiber optic cables provide the highest bandwidth and potential speeds, making them the best choice for modern high-speed internet connections, especially for backbone internet infrastructure. Coaxial cables offer moderate bandwidth and are commonly used for cable internet connections, supporting hundreds of Mbps. Twisted pair cables, depending on the category, can support speeds suitable for home and office networks.
• Cost: Twisted pair cables are usually the most cost-effective for short distances and are widely used in local area networks. Coaxial cables are moderately priced but less commonly used for new network installations, often being replaced by fiber optics in many applications. Fiber optic cables are typically the most expensive, both in terms of materials and the specialized skills required for installation, but the cost has been decreasing as the technology becomes more widespread.
• Distance: For data transmission over long distances without significant signal loss, fiber optic cables are superior. Twisted pair cables are usually limited to 100 meters for Ethernet networks, while coaxial can run longer but with signal boosters. Fiber optic cables can run for tens of kilometers, making them ideal for connecting network segments that are far apart.

In summary, twisted pair cables are suitable for most local area networks where high speed is not the primary concern, and cost-effectiveness is valued. Coaxial cables are still in use for many types of broadband connections, but their role in data networks is diminishing in favor of fiber optics. Fiber optic cables are the best choice for new installations where high speed, high bandwidth, and long-distance communication are required, despite the higher initial costs.

Network Interface Controller

• Without a network interface controller (NIC), a computer cannot connect to a network.
• An NIC allows both wired and wireless communications between computers on a LAN or connected to a large-scale network using the Internet Protocol (IP).
• An NIC is both a physical layer and data link layer device, providing the necessary circuitry for physical layer processes and some data link layer processes to run on it.

Wireless access point (WAP)

Wireless Access Points (WAPs or simply APs) are networking devices that allow wireless-capable devices to connect to a wired network using Wi-Fi, or related standards. They act as a central transmitter and receiver of wireless radio signals. Mainstream wireless APs support Wi-Fi and are used in homes, public internet hotspots, and business networks to accommodate wireless mobile devices.

Hub

• A hub allows you to connect multiples devices to one network.
• It operates on the physical layer and is considered a passive device. In other words, it simply broadcasts the transmissions it receives to all other connected devices
• Unfortunately, that means the network can easily become flooded with unnecessary traffic.
• It is purely a hardware device — there is no software installed on it.
• Hubs are typically much slower than switches in terms of data transfer.

Switch

• A switch also allows you to connect multiples devices to one network.
• It operates on the data link layer and is an active device, meaning it can inspect transmissions and route them to the correct device, keeping unnecessary traffic to a minimum.
• A switch typically has software installed on it for administration and configuration purposes.
• Switches are typically much faster than hubs in terms of data transfer.

Summary Question:

What hardware is required to build and connect to a network?