Cis 160 Ch#1 Intro To Networks & Data Comm.

Front 1

Name the 5 types of networks. Give their acronym and long name.

Back 1

TAN-Tiny Area Network,
LAN-Local AN, WAN-Wide AN,
MAN-Metropolitan AN, PAN - Personal AN

Front 2

data communications

Back 2

the transfer of digital or analog data using digital or analog signals

Front 3

Define MODEM

Back 3

Modulator-Demodulator. digital data transmitted by analgo signals

Front 4

Define Codec

Back 4

device accepts analog data converts it and transmits it by digital signals

Front 5

List 6 parts of a network

Back 5

1) Work station 2) Servers
3) Bridges 4) Routers 5) Hubs
6) Switches

Front 6

What types of devices are included in a LAN? What is the range?

Back 6

6 Parts of a network. Range = spans a room, floor of a building, a buiding or a campus.

Front 7

What is the range of a WAN?

Back 7

Range= parts of states, multiple states, countries, the world

Front 8

What is the range of a MAN?

Back 8

Range of a MAN = roughtly 50 kilometers, approximately the area of a typical city.

Front 9

List the range and devices of a typical PAN?

Back 9

PAN spans an area of several meters. Devices include laptops, PDAs, and wireless connections

Front 10

Workstation

Back 10

personal computers or microcomputers

Front 11

Servers

Back 11

computers that store network software and shared or private user files

Front 12

Hubs

Back 12

collection points for the wires that interconnect the workstations

Front 13

Switches

Back 13

more advanced devices that replacing hubs and are capable of filtering out unnecessary traffic

Front 14

Routers

Back 14

connecting devices between local area networks and wide area networks

Front 15

Nodes

Back 15

computing devices that allow workstations to connect to the network, also makes the decisions where to route a piece of data

Front 16

Terminal to mainframe configuration

Back 16

dumb terminal used for entering data into a system usually transmitted at low speeds.

Front 17

PC to mainframe

Back 17

download info from mainframe to PC, perform computations, then upload to mainframe

Front 18

PC to LAN

Back 18

Allows for sharing software and peripherals.

Front 19

PC to Internet

Back 19

Users connect at dial up speeds of 56 Kbps or higher using DSL or cable modems

Front 20

LAN to LAN

Back 20

connect 2 LANS so that they for sharing. Connected by switch, bridge, router. 2 LANs necessary to separate access.

Front 21

PAN to workstation

Back 21

transfer voice, data, music from handheld devices to microcomputers etc wirelessly

Front 22

LAN to MAN

Back 22

Connecing businesses within a metro area, using fiber-optic at extremely high speeds

Front 23

LAN to WAN

Back 23

User on LAN connects to Internet via a router (which converts data and provides security)

Front 24

Sensor to LAN

Back 24

action triggers a sensor that is connected to a network (traffic intersection)

Front 25

Satellite & microwave connections

Back 25

Connect networks over great distances

Front 26

Wireless

Back 26

data transfer over cellular system

Front 27

Name 2 network architecture models

Back 27

OSI-Open Systems Interconnection, TCP/IP

Front 28

Name the layers of the OSI model

Back 28

Application, Presentation, Session, Transport, Network, Data Link, Physical

Front 29

what neumonic helps you remember the layers of the OSI model?

Back 29

All People Should Try New Dairy Products

Front 30

What is the designated function of the Application Layer of the OSI model?

Back 30

Where the application using network resides

Front 31

What is the function of the Presentation Layer in the OSI model?

Back 31

data is converted, encrypted, decrypted, compressed etc.

Front 32

What is the function of the Session Layer in the OSI Model?

Back 32

establishes sessions, token mgt., synchronization

Front 33

What is the function of the Transport Layer?

Back 33

Ensures no errors, duplication & that the data packet that arrives at the final destination is identical to the packet that left.

Front 34

What is the prupose of the Network Layer in the OSI model?

Back 34

To create, maintain, terminate network connections

Front 35

What is the purpose of the Data Link Layer in the OSI model?

Back 35

transform data from the network layer into a cohesive unit call a frame.

Front 36

What is the function of the Physical Layer in the OSI Model?

Back 36

handles the transmission of bits over a communication channel.

Front 37

What are the layers of the TCP/IP protocol suite?

Back 37

Application, Transport, Network, Network Access

Front 38

Compare the Application Layer of the OSI model with the TCP/IP protocol suite

Back 38

In TCP/IP Application layer supports the network applications & may include presentation services.

Front 39

Which network architecture uses the following applications: FTP, Telnet, SMTP, SNMP, HTTP?

Back 39

TCP/IP application layer

Front 40

What is FTP used for?

Back 40

to transfer files from one computer system to another

Front 41

What is telnet used for?

Back 41

allows aremote user to log in to another computer system

Front 42

What is HTTP used for?

Back 42

to allow Web browsers and servers to send and receive WWW pages.

Front 43

What is SMTP used for?

Back 43

Simple Mail Transfer Protocol allows users to send and receive e-mail.

Front 44

What protocol does the transport layer use in the TCP/IP protocol suite?

Back 44

Transmission Control Protocol which maintains an error-free ent to end connection.

Front 45

What protocol is used in the Network layer of the TCP/IP protocol suite?

Back 45

Internet Protocol - sometimes call the Internet layer.

Front 46

What is the netework Access layer in TcP/IP equivalent to in OSI model?

Back 46

physical and data link layers. defines the physical medium that transmits signal and frame for flow and error control.

Front 47

Logical vs. Physical connections in communication models

Back 47

logical is nonphysical between sender and receiver. physical-direct connection between sender and receiver at physical layer.

Front 48

Spectrum

Back 48

Range of frequencies a signal spans, minimum to maximum.
telephone = 300Hz to 3400 Hz

Front 49

Phase change or phase shift

Back 49

jumping forward or backward a number of degrees

Front 50

Attenuation

Back 50

logarithmic loss of signal power due to friction

Front 51

Decibel

Back 51

logarithmic value
3 dB loss is 50%

Front 52

Encoding is a method for what?

Back 52

converting data to signals

Front 53

List the 6 most representative digital encoding schemes:

Back 53

NRZ-L, NRZ-I, Manchester, differential Manchester, bipolar-AMI, 4B/5B

Front 54

What is NRZ-L?

Back 54

non-return to zero
1s are 0 volts
0s are positive volts
receiver has to check voltage level for each

Front 55

What is NRZ-I?

Back 55

non-return to zero inverted
voltage change at beginning of a 1, no change at beginning of 0, receiver only has to look for a change

Front 56

What is Manchester encoding?

Back 56

0-changes from high to low in middle, 1 changes from low to high in middle. Always a change mid-bit. can change twice. changes per sec = baud rate

Front 57

What is 4B/5B?

Back 57

takes 4 bits of data and converts to 5 bits.

Front 58

What are 2 advantages of NRZ-L?

Back 58

1) simple to generate
2) inexpensive to implement in hardware

Front 59

What is teh fundamental difference between NRZ-L and NRZI?

Back 59

With NRZ-L receiver has to check the volt level for each bit to determine 0 or 1. NRZI receiver checks for change at beginning of bit.

Front 60

What is the inherent problem of the NRZ-L, NRZI schemes?

Back 60

Long sequences of 0s produce a signal that never changes. can't tell when one bit ends, next bit begins. signal changes for synchronization.

Front 61

Name a class of digital encoding scheme that solves the synchronization problem? How?

Back 61

Manchester Class. ensures each bit has some type of signal change.

Front 62

Which scheme is used over most LANs for transmitting digital data?

Back 62

Manchester

Front 63

In which scheme is there always a transition in the middle of a bit?

Back 63

Manchester schemes

Front 64

Is a transition mid-bit an advantage or disadvantage over NRZ-L,NRZI? Why or why not?

Back 64

Advantage. Receiver can expect a signal change at regular intervals and can synchronize

Front 65

Name 3 methods for transmitting digital data with analog signals:

Back 65

AM, FM, & Phase modulation

Front 66

Describe AM

Back 66

Amplitude modulation - low is 0, higher is 1. 4 amps to show 00,01,10,11. Noise =problem. <= 1200 bps

Front 67

Describe FM

Back 67

Frequency modulation.lower frequency to represent 1. Higher Freq = 0. Intermodulation distortion when signals mix

Front 68

Describe Phase modulation

Back 68

most accurate. 45 deg = 11, 135 deg = 10, 225 deg = 01, d15 deg = 00. quadrature amp modulation. 1 signal change = 2 bits, 1 baud=2 bps. Most MODEMS use this.

Front 69

Name 2 ways to transmit analog w/digital

Back 69

Pulse code & Delta modulation

Front 70

Describe Pulse code

Back 70

take snapshots at fixed intervals, pulse amp modulation, reconstruction can be poor

Front 71

Describe Delta modulation

Back 71

assissing up or down steps, first converts to PAM value, then to binary. May not keep up w/quick rise or all. Slope overloadd noise occurs

Front 72

Which technology is used by wireless devices?

Back 72

Spread Spectrum technology. prevents eavesdropping on cordless phones.

Front 73

Define "data codes"

Back 73

The set of all textual characters or symbols and their corresponding binary patterns

Front 74

Name 3 data codes:

Back 74

EBCDIC, ASCII, and Unicode

Front 75

What does EBCDIC stand for?

Back 75

Extended Binary Coded Decimal Interchange Code

Front 76

How many bits are used in EBCDIC? How many combinations?

Back 76

8 bits, 256 combinations to represent text, numbers, symbols

Front 77

What does ASCII stand for?

Back 77

American Standard Code for Information Interchange

Front 78

How many bits and possible cominations are possible in ASCII?

Back 78

7 bits w/parity check or 8 bit no parity; 128 combinations; 256 possible combinations

Front 79

How does ASCII use the last bit in a BYTE?

Back 79

used to check for transmission errors or to provide 128 additional characters

Front 80

Where does name Unicode come from?

Back 80

Encoding technique provides Unique Coding value for every character in every language, no matter what platform.

Front 81

Name 3 ways that EBCDIC & ASCII were limited:

Back 81

1) Only represent symbols found in English. 2) Can't represent all English symbols. 3) Can't represent other languages.

Front 82

How many code charts does Unicode support?

Back 82

110. ASCII is one of them.

Front 83

How many bits for Unicode? How many combinations?

Back 83

16 bit, more than 64,000 combos.

Front 84

How is shielded twisted pair different from unshielded twisted pair?

Back 84

Shielding is wrapped around each wire, or all wires together or Both.

Front 85

What is crosstalk?

Back 85

current or signal in 1 wire produces an unwanted current or signal in the other wire.

Front 86

What are the characteristics of Cat 1 wire?

Back 86

used for POTS; analog voice or digital data up to 9600 bps

Front 87

What are the characteristics of Cat 2 wire?

Back 87

higher quality than cat 1; T1(1.544 Mbps); ISDN; better copper and better insulation.

Front 88

What are the characteristics of Cat 3 wire?

Back 88

10 Mbps; LAN up to 100 meters; Repeaters after 100 m

Front 89

What are the characteristics of Cat 4 wire?

Back 89

20 Mbps; up to 100 meters

Front 90

What are the characteristics of Cat 5 wire?

Back 90

100 times faster than Cat 3; 100 Mbps; LAN up to 100 m; 100 MHz