Intro to Data Communications - CH 1 (EXAM 1)

Question 1

client

Answer 1

user device to access network and receive data from a server

compter (client) –> server

Question 2

server

Answer 2

device that stores and transmits data to client

computer –> upload files –> server

Question 3

circuit

Answer 3

connection between client and server

Question 4

why are networks important?

Answer 4

efficient data transmission, real-time communication, web

Question 5

what are the 4 network types?

Answer 5

LAN
BN
MAN
WANs

Question 6

What is a LAN?

Answer 6

Local Area Network

room, building, group of PC’s sharing network

Question 7

What is a BN?

Answer 7

Backbone networks

less than a few km’s
high-speed backbone linking together LAN’s at various locations

Question 8

What is a MAN?

Answer 8

Metropolitan area networks

more than a few kms
connects LAN’s and BN’s across locations
uses lease lines to transmit data

Question 9

What is a WAN?

Answer 9

Wide area network

more than 10 kms
greater scale than MAN

Question 10

What are the 2 types of networks?

Answer 10

intranet and extranet

Question 11

What is the intranet?

Answer 11

network (LAN) that shares information IN an organization

Question 12

What is the extranet?

Answer 12

a network that shares information BETWEEN organizations

invited users outside the org.
access through the internet

Question 13

What are network models?

Answer 13

divide communication functions into layers

Question 14

What are the 2 types of network models?

Answer 14

OSI model

Internet model

Question 15

What is the OSI model?

Answer 15

7 layers

physcial, DL, network, transport, session, presentation, application

Question 16

What is the Internet model?

Answer 16

5 layers
based on TCP/IP

physical, link, network, transport, application

Question 17

What is a protocol?

Answer 17

defines the language of transmission and specifies rules, function, and messages for the communication at a layer

Question 18

What is a protocol data unit (PDU)?

Answer 18

contains layer SPECIFIC information for a message to be transmitted through a network

encapsulation occurs when a higher level PDU is placed in a lower PDU

Question 19

Application layer

Answer 19

user’s access to network
software to perform work

protocols: HTTP, SMTP, DNS, FTP, DHCP, IMAP, POP, SSL
PDU: packet (data)

Question 20

Transport layer

Answer 20

end to end management

links application layer to network, segment and track, flow control

protocols: TCP and UDP
PDU: segment

Question 21

Network layer

Answer 21

decides where the message goes (address and route)

protocols: IP and ICMP
PDU: packet

Question 22

Data Link layer

Answer 22

moves a message from one device to next
controls hardware, formats message, error checking

protocols: ethernet, T1, frame relay
PDU: frame

Question 23

Physical layer

Answer 23

transmits a message through a circuit

protocols: 100BASE-T, 802.11n, category 5 cable

Question 24

What are the advantages of layers?

Answer 24

easy to troubleshoot

app developers can worry about the app layer in programs

Question 25

What are the disadvantages of layers?

Answer 25

encapsulation and decapsulation at each layer before processing

encapsulation in PDU increases overhead at each layer

Question 26

What are network standards?

Answer 26

ensures hardware and software from different vendors can work together and “speak the same language”

Question 27

What are the de jure standards?

Answer 27

formalized by industry or government body
CIA, FBI

HTTP, IEEE, 802.3, 802.11n

Question 28

What are de facto standards?

Answer 28

widely accepted, not normalized

MS windows

Question 29

What is the de jure standardization process?

Answer 29

specification, choice identification, acceptance

Question 30

What is specification?

Answer 30

identifying problems to be addressed

Question 31

What is the identification of choices?

Answer 31

identify solutions and choose optimum solutions

Question 32

What is acceptance?

Answer 32

defining a solution and recognized by industry