Lesson 4.2: Network Hardware

Question 1

A transmission medium

Answer 1

A transmission medium (the singular form of the word “media”) is simply a component that carries data from one network device to another. There are two types of transmission media: wired and wireless.

Question 2

network

Answer 2

A network is a collection of two or more connected devices that can communicate with one another.

Question 3

Transmission Media

Answer 3

Data travels through a network using communication channels that connect the network components. Both wired and wireless networks require network media to transfer data. Twisted pair cables, coaxial cable, and optical fiber cables are common network media used in wired networks, while wireless networks use radio waves, microwaves, and infrared waves.

Twisted pair cables are the most widely used type of transmission media. Two common types of twisted pair cables are unshielded twisted pair (UTP) and shielded twisted pair (STP).

STP cables consist of two separately insulated copper wires wound around each other, making them more expensive than UTP cables. The insulating sheath on STP cables protects the wires from things like neighboring unshielded cables and electromagnetic interference from fluorescent lights.

Twisted pair cables come in various bandwidth capacities with a maximum segment length of 100 meters (328 feet).

Question 4

Network Bandwidth

Answer 4

CAT1 1 Mbps

CAT2 4 Mbps

CAT3 10 Mbps

CAT4 16 Mbps

CAT5 100 Mbps

CAT5e 1 Gbps

CAT6 10 Gbps

CAT7 10 Gbps

Question 5

coaxial cables

Answer 5

Coaxial cables (often referred to as “coax”) have an outer plastic that is used in computer networks and to deliver cable TV services. First used commercially used in the 1940s, it is used for both baseband and broadband data communication services. The bandwidth of coaxial cables is about 80 times the bandwidth of twisted wires. Cable modems and televisions typically use coaxial cables.

Baseband is a signal at a very narrow frequency range on which data or information is superimposed and then transmitted. Examples include Ethernet LANs and serial cables.

Broadband is considered high-capacity transmission technologies that are used to transmit data, voice, and video across long distances and at high speeds. Examples include coaxial cable, fiber optic cable, and radio waves.

Question 6

Fiber-Optic Cable

Answer 6

Fiber-optic cable uses the concept of reflection of light through a core made up of glass or plastic. The core is surrounded by a less dense glass or plastic covering called the cladding. Fiber-optic cable are able to transmit large volumes of data. Their bandwidth can provide up to 26,000 times the bandwidth of the twisted pair wires, at the time of this writing.

Question 7

Wireless Transmission

Answer 7

The use of wireless transmission media is sometimes more convenient and practical than installing cables. Electromagnetic waves of different frequencies, such as infrared or radio waves, can be used to transmit data within a network with the use of Wi-Fi, Bluetooth, or even near field communication. These radio waves are what is used to carry radio signals far distances to other networked devices.

Many believe Wi-Fi stands for wireless fidelity. However, it is just a play on words according to the Institute of Electrical and Electronics Engineers (IEEE), and it was created by a marketing team. Wi-Fi adapters are commonly installed on mobile computer devices such as laptops, tablets, and smartphones. Wi-Fi adapters enable devices to connect to each other or to the internet. Each of these wireless transmission methods has its own protocols to identify how to connect and transmit or receive data. Each uses different frequencies, which makes it possible for data to travel over small and large distances.

These wireless technologies are examples of wireless media that can exchange data, such as sending audio to a Bluetooth speaker, sending files from one PC to another, or making a payment with your smartphone at the grocery store through near field communication (NFC). Bluetooth supports distances shorter than 30 feet, while Wi-Fi devices can be accessed up to 300 feet away.

Question 8

Laptop

Answer 8

A laptop computer is a portable personal computer with a folding design. It includes an
integrated flat screen, a keyboard with a mouse, and usually, a battery. It can also contain a
CDROM, DVD-ROM, as well as various other devices such as SD card readers, Wi-Fi, Bluetooth,
etcetera. Laptops typically connect to networks via Wi-Fi or Ethernet.

Question 9

Router

Answer 9

Routers are special-purpose computers that forward messages to and from the machines on
their network. They use their forwarding table to match up the private IP address with the
internet IP address and send the message to the correct machine.

Question 10

Printer

Answer 10

Printers can reside on networks through the router or a switch, making them accessible to all
the other network devices. Printers typically connect to networks via Ethernet but can also use
Wi-Fi.

Question 11

Firewall

Answer 11

A firewall monitors network traffic and blocks traffic that triggers its safety rules, providing a
barrier between a trusted private network and an untrusted network like the internet.

Question 12

Modem

Answer 12

A modem bridges between the customer network and the ISP, converting the incoming analog
data into digital, and the outgoing digital data into analog. It provides the access point to the
internet.

Question 13

Internet

Answer 13

This term is often confusing. To ensure the proper meaning of the term, pay attention to
whether or not it is capitalized. The Internet (with a capital I) generally refers to the worldwide
Internet and is most often what non-technical people are referring to when they speak of the
Internet. However, an internet is simply a network of networks. Often, when IT professionals
refer to the internet, they are referring to a network of networks.

Question 14

Tablet Computer

Answer 14

A tablet computer is a portable computer typically with touchscreen display and a rechargeable
battery in a thin and flat design. Typically, it connects to a network via Wi-Fi.

Question 15

Smartphone

Answer 15

A smartphone is a cellular phone with an operating system and the ability to run third-party
applications. Typically, smartphones connect to networks using cellular wireless frequencies or
Wi-Fi on local networks.

Question 16

Switch

Answer 16

A network switch extends the network by using packet switching to forward data to the
intended hard-wired devices.

Question 17

Desktop Computer

Answer 17

Typically, a tower chassis enclosure which contains the internal components of the computer
system, an external display that provides output, and a keyboard and mouse to provide input.
Desktops typically connect to a network via Ethernet but can also utilize Wi-Fi.

Question 18

Server

Answer 18

A server is a computer that provides services, such as website hosting and routing, for other
devices.

Question 19

combining networks

Answer 19

Local Area Networks (LAN) can be connected to create a larger network and sometimes become Wide Area Networks (WAN). These connected networks can expand and increase communication and effectiveness of the organization. The following devices can be used to connect networks:

Repeaters extend the range of cabling types so connections can be made by increasing the strength of the network signal. For example, if two twisted pair cabling networks are 500 feet apart, a repeater can be used to extend the 300 feet range of twisted pair cabling to 500 feet. Repeaters can be used on fiber and coaxial also.

Bridges are used to connect to different types of network and provide management of the message. For example, a bridge can connect a twisted pair and coaxial network. The bridge analyzes the network message and will only bridge the network if a message is addressed to a device on the other side.

Switches are used on LANs to reduce network traffic by management of network messages. Older devices would broadcast all messages to all devices on the LAN. For example, on a 100-device network, a switch would only send one message to the destination device. This management example would create 99% less traffic.

Routers are the device that makes the internet possible. A router connected to your LAN acts as gateway to the internet. (This device on your LAN can be also be called a Gateway.) Routers manage network traffic by having a routing table of know devices. If a destination address is unknown to the Router, it will forward the message to another router. This analyze and forward process continues until the message reaches the correct address.