Chapters 1 & 2

Question 1

Computer Network

Answer 1

Any telecommunication connection that allows computers to electronically exchange data

Question 2

Internet

Answer 2

Any set of (inter)connected networks

Question 3

Intranet

Answer 3

Network that is not available to the outside world

Question 4

The Internet

Answer 4

Global system of interconnected computer networks that uses TCP/IP protocol suite to link billions of computers worldwide

formed by connecting multiple packet switching networks

Question 5

World Wide Web (WWW)

Answer 5

System of interlinked hypertext documents that are accessed via the Internet using the web browsers

Question 6

Y/N All computer networks are internets

Answer 6

no

Question 7

Y/N Any internet is a computer network

Answer 7

YEs

Question 8

Y/N The internet is a computer network

Answer 8

Yes

Question 9

Y/N The Internet is an internet

Answer 9

Yes

Question 10

Y/N The WWW is a computer network

Answer 10

No, WWW does not connect computers, it connects files. It is an application, just like email.

Question 11

message

Answer 11

information to be communicated

Question 12

sender

Answer 12

device that sends the message

Question 13

receiver

Answer 13

device that receives the message

Question 14

medium

Answer 14

physical path from sender to receiver

Question 15

protocol

Answer 15

set of rules that govern data communications

Question 16

The Internet uses this protocol suite

Answer 16

TCP/IP

Question 17

circuit switching

Answer 17

(dedicated line) method of implementing network communication in which two network nodes require a dedicated communications channel/wire (circuit) to communicate (like phone communication)

Question 18

packet switching

Answer 18

(small packets travel independently) Data is divided into small “packets” and packets travel independently through the network to reach the recipient

Question 19

Protocol layer

Answer 19

subset of specific aspects of communication

Each protocol should handle a part of communication that is not handled by other protocols

Question 20

Layers

Answer 20

each layer implements a service
- via its own internal-layer actions and procedures
- relying on services provided by layer below

Each layer of protocol verifies that the messages arrive as expected

Question 21

Why layering?

Answer 21

Helps deal with complex systems
- Provides a conceptual framework that can help us understand the system
- Easier maintenance or updating of system

Question 22

Encapsulation

Answer 22

change of implementation of layer’s service is invisible to rest of system

Question 23

Internet Layered Model (Protocol Stack)

Answer 23

Application
Transport
Internet
Link (network interface)
Physical

Question 24

Application (Layer 5)

Answer 24

for network applications

ex)
- email exchange
- file transfer
- web browsing - HTTP & HTML protocols
- telephone services

Protocols: FTP, SMTP, HTTP

Question 25

Transport (Layer 4)

Answer 25

Provide communication from an application program on one computer to an application program on another; controlling the maximum data rate a receiver can accept, how to avoid network congestion, techniques to ensure that all data is received in the correct order process-process data transfer Protocols: TCP, UDP

Question 26

Internet (Layer 3)

Answer 26

Fundamental for the Internet; specify communication across the Internet (spanning multiple interconnected networks) routing of datagrams from source to destination Protocols: IP, routing protocols

Question 27

Network Interface Layer; Link (Layer 2)

Answer 27

Specify details about communication between higher layers of protocols (implemented in software) and the underlying network (implemented in hardware): network addresses, maximum packet size that a network can support, how to access the underlying medium, hardware addressing data transfer between neighboring computers Ethernet, PPP, wireless

Question 28

Physical (Layer 1)

Answer 28

How electrical and electromagnetic energy is used to carry information across wires, glass, or through the air bits "on the wire" Protocols: Manchester encoding, ASCII

Question 29

header

Answer 29

To perform verification on packages - each layer on the sender prepends extra information onto the packet - The corresponding protocol layer on the receiver removes and uses the extra information - Application layer doesn't prepend information (up to down)

Question 30

message

Answer 30

HTTP, FTP, DNS

Question 31

segment

Answer 31

TCP or UDP

Question 32

IP datagram

Answer 32

internet layer

Question 33

frame

Answer 33

Ethernet

Question 34

IP address

Answer 34

Each computer connected to the Internet is given a unique address

Question 35

IP meaning

Answer 35

internet protocol IPv4: series of four numbers separated by dots (147.53.6.172)

Question 36

The internet structure is a

Answer 36

network of networks because a packet passes through many networks.

Question 37

Protocols define...

Answer 37

format, order of messages sent and received, actions taken upon message transmission or receipt