Connecting with Computer Science Chapter 4 Review:
Chapter Summary:

Networking is essential to modern computing.

Networking requires a transmission medium to carry information from one computer device to
another.

Transmission media are rated in terms of their: bandwidth, signal-to-noise ratio, bit error rate and
attenuation.

Copper wire has been the most widely used network conductor, primarily in the form of coaxial and
twisted pair cable.

Fiber-optic cable has a much higher band-width than copper conductors.

Cat 5 is a twisted pair copper cable used most commonly in Ethernet networks; it has a transmission
speed of up to 100 Mbps.

Wireless technologies allow networking to be conducted by using electromagnetic waves or light.

The IEEE 802.11 family of standards applies to wireless networking.

A protocol is a set of rules designed to facilitate communication and is essential to networking.

The OSI defines a set of protocols necessary for data communication; the 7 protocol layers are:
Physical, Data Link, Network, Transport, Session, Presentation, Application.

The main network types are: WAN, LAN, WLAN.

LAN topologies are: Star, Ring and Bus.

The most popular LAN technology is Ethernet, and token ring is another LAN technology.

Various hardware devices are used in networking, such as NICs repeaters, hubs, switches, bridges,
gateways routers and firewalls.

Voice telephone service is widely used to extend networks, and modems handle the conversion from
digital binary to analog audio to make using voice networks possible.

Transmission media are shared among users by using FDM and TDM techniques.

DSL, cable modems, and satellite are popular broadband WAN solutions.
Connecting with Computer Science Chapter 4 Review:
Key Terms:
10BaseT: (140)
100BaseT: (141)
10GBaseT: (141)
802.11: (144)
AM: (155)
ATM: (152)
Attenuation: (138)
Bandwidth: (138)
Bit Error Rate: (138)
Bluetooth: (144)
Bridge: (153)
Cable Modem: (159)
Cat5: (141)
CCITT: (147)
Coaxial: (139)
Datagram: (147)
DSL: (158)
Ethernet: (152)
FDDI: (152)
FDM: (158)
Fiber Optic: (141)
Firewall: (154)
FM: (155)
Gateway: (154)
Guided Media: (139)
Hub: (153)
IEEE: (142)
Impedance: (140)
Inductance: (140)
ISO: (146)
ISO OSI ref Model: (146)
LAN: (149)
Modem: (155)
NIC: (153)
Network topology: (150)
Node: (150)
PDU: (148)
PM: (155)
Protocol: (144)
Repeater: (153)
Router: (154)
Signal-to-Noise Ratio: (138)
Switch: (153)
A twisted pair Ethernet networking cable capable of transmitting at rates up to 10 Mbps
A fast Ethernet networking cable made up of 4 twisted pairs of wire and capable of transmitting at 100Mbps
The fastest Ethernet networking cable, capable of transmitting at 10Gbps over twisted pairs of wire.
A family of specifications for WLANs developed by IEEE; Currently includes: 802.11, 802.11a, 802.11b, 802.11g, 802.11n
(Amplitude Modulation) A technique of placing data on an alternating carrier wave by varying the signal’s amplitude; this technique
is often in modems.
A network technology based on transferring data in cells or packets of a fixed size at speeds up to 2.488 Gbps
A reduction in the strength of an electrical signal as it travels along a medium
A measurement of how much information can be carried in a given time period over a wired or wireless communication medium
usually measured in bps.
The percentage of bits that have errors in relation to the total number of bits received in a transmission; a measure of the quality of a
communication line.
A specification for short-range RF links between mobile computers, mobile phones, digital cameras and other portable devices.
A special type of network switch that can be configured to allow only specific network traffic through, based on the destination
address.
A type of digital modem that connects to a local cable TV line to provide a continuous connection to the Internet.
A popular Ethernet twisted pair communication cable capable of carrying data rates up to 100Mbps
A standards group involved in the development of the ISO OSI reference model.
Communication cable that consists of a center wire surrounded by insulation and then a grounded foil shield wrapped in steel or
copper braid.
A packet of information used in a connectionless network service that is routed to its destination by using an address included in the
datagram’s header.
(Digital Subscriber Line) A method of sending and receiving data over regular phone lines, using a combination of FDM and TDM
A common method of networking computers in a LAN, using copper cabling at speeds up to 100Mbps
(Fiber Distributed Data Interface) A token passing, fiber optic cable protocol with support for data rates up to 100 Mbps; FDDI
networks are typically used as the main lines for WANs.
(Frequency-Division multiplexing) A technique for combining many signals on a single circuit by dividing available transmission
bandwidth by frequency into narrow bands, each used for a separate communication channel.
Guided network cable consisting of bundles of thin glass strands surrounded by a protective plastic sheath
A network device that protects a network by filtering out potentially harmful incoming and out-going traffic.
(Frequency Modulation) A technique of placing data on an alternating carrier wave by varying the signal’s frequency; this techniques
is often used in modems.
A network component, similar to a bridge that allows connecting networks of different types.
Physical transmission media, such as wire or cable.
A network device that functions as a multiport repeater; signals received on any port are immediately retransmitted to all other on
the hub.
An organization involved in formulating networking standards.
The opposition a transmission medium has toward the flow of alternating electrical currents
The magnetic field around a conductor that opposes changes in current flow
An organization that coordinates worldwide standards development.
A data communication model consisting of seven functional layers.
A network of computers in a single building or in close proximity.
A device that converts binary signals into audio signals for transmission over standard voice-grade telephone lines and converts the
audio signals back into binary.
A circuit board that connects a network medium to the system bus. And converts a computers’ binary information into a format
suitable for the transmission medium; each NIC has a unique 48-bit address.
A schematic description of the arrangement of a network, including its nodes and connecting lines.
Any addressable device attached to a network that can recognize, process or forward data transmissions.
(Protocol Data Unit) A data communication packet containing protocol information in addition to a data payload.
(Phase Modulation) A technique of placing data on an alternating carrier wave by varying the signal’s phase; the most common
modulation type in modems.
A set of rules designed to facilitate communication; protocols are heavily used in networking.
A network device used to amplify signals on long cables between nodes.
A network device, similar to a gateway that directs network traffic, based on its logical address
A measure of the quality of a communication channel.
A network repeater with multiple inputs and outputs; each input can be switched to any of the outputs, creating a point-to-point
circuit.
Connecting with Computer Science Chapter 4 Review:
Key Terms: (cont…)
T1-LIne: (157)
TDM: (158)
Token Ring: (152)
Transmission Medium: (138)
Twisted Pair: (139)
Unguided Media: (139)
WAN: (149)
WLAN: (149)
A digital transmission link with capacity of 1.544 Mbps; T1 uses two pairs of normal twisted wires, the same used in most homes.
(Time Division Multiplexing) A technique for combining many signals on a single circuit by allocating each signal on a single circuit by
allocating each signal a fixed amount of time but allowing each signal the full bandwidth during an allotted time.
A LAN technology that has stations wired in a ring, in which each station constantly passes a special message token on to the next;
whichever station has the token can send a message.
A material with the capability to conduct electrical and/or electromagnetic signals.
A pair of insulated wires twisted together and used as a transmission medium in networking.
Transmission media that you cannot see, such as air or space, that carry radio or light signals.
A network in which computer devices are physically distant from each other, typically spanning cities, states or even continents.
A local network that uses wireless transmission instead of wires; the IEEE 802.11 protocol family is often used in WLAN’s.
Connecting with Computer Science Chapter 4 Review:
Test yourself:
1.) What are 2 types of transmission media?
 2 types of transmission media are: Guided and Un-guided media.
2.) What are the four ways to rate transmission media?
 The 4 ways to rate transmission media are:




Band Width.
Signal-to-noise ratio.
Bit error rate.
Attenuation.
3.) What are the 2 basic copper wire formats?
 The 2 basic copper wire formats are:
 Twisted pair.
 Coaxial.
4.) What is the maximum frequency of Cat 5 cable?
 The maximum frequency of Cat 5 cable is: 100MHz.
5.) What are examples of networking protocols?
 Examples of networking protocols are:
 HTTP protocol.
 FTP protocol.
6.) How many layers are there in the OSI model?
 There 7 layers in the OSI model.
7.) What is WAN?
 WAN stands for Wide Area network. It allows for computers to connect internationally.
8.) What are the 3 LAN topologies?

Three LAN topologies are:
 Bus.
 Ring.
 Star.
9.) Which of the 3 LAN topologies has emerged as the most popular?

With the advent of the internet; The Star topology has increased in popularity.
10.) What is a NIC?
 A circuit board that connects a network medium to the system bus. And converts a computers’
binary information into a format suitable for the transmission medium; each NIC has a unique 48-bit
address.
11.) Which network device can interpret and translate different network protocols?
 Routers.
12.) What is the difference between a hub and a switch?
 The difference between a switch and a hub is:
 Switch: Not all the inputs and outputs are connected. Instead, the switch examines the input’s
packet header and switches a point-to-point connection to the output addressed by the packet.
 Hub: All the inputs and outputs are connected.
13.) Which network device is designed to prevent damage to an inside network from an outside source?
 Firewall.
14.) What frequency range are voice-grade telephone lines designed to carry?
 The frequency range voice-grade telephone lines carry are designed to carry are: 300 to 3300Hz.
15.) What is the speed range for DSL?
 The speed range for DSL is: 256 Kbps to 1.5Mbps.
16.) What is bandwidth?
 A measurement of how much information can be carried in a given time period over a wired or
wireless communication medium usually measured in bps.
17.) How does a WLAN differ from a LAN?
 WLAN differs from LAN in that WLAN is a wireless topology that spans continents as opposed to
being confined to one building, structure or area.
18.) What is the difference between AM and FM?
 The difference between AM and FM are as follows:
 AM: (Amplitude Modulation) A technique of placing data on an alternating carrier wave by
varying the signal’s amplitude; this technique is often in modems.
 FM: (Frequency Modulation) A technique of placing data on an alternating carrier wave by
varying the signal’s frequency; this techniques is often used in modems.
19.) How many standard voice lines are equivalent to a T1 line?
 There are: 28 standard voice lines on a T1 line.
20.) Which type of multiplexing combines signals on a circuit by dividing available transmission bandwidth
into narrow bands?
 FDM: (Frequency Division Multiplexing) combines signals on a circuit by dividing available
transmission bandwidth into narrow bands.
Connecting with Computer Science Chapter 4 Review:
Practice Exercises
1.) Which is a better signal-to-noise ratio?
 A. High.
2.) Fiber-optic cable is made of:
 A. Glass.
3.) Which is a faster networking cable?
 B. 100BaseT.
4.) Which of the following standards IS USED in wireless networking?
 C. 802.11
5.) Which of the following IS NOT one of the OSI model layers?
 B. Wireless
6.) Which of the OSI layers is responsible for guaranteed delivery of data?
 C. Data-Link
7.) Which of the OSI layers is involved with a network’s electrical specifications?
 A. Physical
8.) Which of the following is a LAN topology?
 C. Star
9.) A hub has a single input and single output.
 B. False
10.) Normal speeds of a cable modem are approximately:
 B. 1 Mbps
11.) DSL speeds range from:
 A. 256 Kbps to 1.5 Mbps
12.) Standard voice-grade lines are designed to carry frequencies in the range of:
 D. 300 Hz to 3300 Hz
13.) Modems convert binary digits into sounds by modulating tones.
 A. True.
14.) Which of the following is not a network device?
 C. Ramp
15.) Which of the following is used to connect a computer to a network?
 B. NIC
16.) What factors reduce the strength of an electrical signal as it travels along a transmission medium?
 D. Attenuation
17.) Which of the following is the most commonly used twisted pair cable category?
 B. Cat 5
18.) Which type of guided medium is the least susceptible to attenuation and inductance?
 C. Fiber-optic cable
19.) Which topology has become more popular with the advent of the Internet and home networking?
 B. Star
20.) DSL is a combination of what two types of multiplexing?
 A. FDM and TDM