lecture 1

Question 1

definition of networking

Answer 1

an interconnected collection of autonomous computers

Question 2

meaning of interconnected

Answer 2

can exchange information via a medium

e.g. fiber, copper, wireless

Question 3

meaning of autonomous

Answer 3

• no-master slave

- if master goes down, slave remains standing/working

Question 4

meaning of a distributed system

Answer 4

the collection of independent computers appears to its users as a single coherent system Single Model

Question 5

difference between a computer network and a distributed network/system

Answer 5

• distributed system: all systems appear as a SINGLE system

- network system: all machines, hardwares and softwares are transparent and visible (you can see all individual systems)

Question 6

example of a distributed system

Answer 6

• World Wide Web

- 1 webpage

Question 7

what is the internet

Answer 7

a global system of interconnected networks, using a standardized Internet Protocol suite for communication and sharing information

Question 8

meaning of telecommunication

Answer 8

communication over a distance

Question 9

meaning of telecommunication

Answer 9

communication over a distance

Question 10

meaning of data communication

Answer 10

the exchange data between two devices via some form of transmission medium such as a wire cable

Question 11

meaning of data communication

Answer 11

the exchange data between two devices via some form of transmission medium such as a wire cable

Question 12

meaning of a network

Answer 12

a set of nodes connected by communication links

Question 13

meaning of a node

Answer 13

any device that is capable of generating and receiving data

Question 14

5 components of a data communication

Answer 14

1. sender
2. receiver
3. medium
4. data/message
5. protocols

Question 15

when do we care about delay (when do we need high latency)

and what do we sacrifice in turn

Answer 15

when it comes to things that are realtime
eg a live stream
- quality

Question 16

when do we care about quality and what do we sacrifice in turn

Answer 16

when it comes to things that are sensitive
eg a bank transaction
- latency

Question 17

telephone lines vs internet

Answer 17

similarity: connect machines together
differences:
- internet use packet switching
- telephone lines use circuit switching

Question 18

components of a computer network

Answer 18

1. hardware
2. software
   - protocols
   - makes hardware convenient (OS)

Question 19

two famous networking commands

Answer 19

• ping

- trace route

Question 20

why are networks used by people

- advantages (5)

Answer 20

1. resource sharing
   – printers, terminals, special architectures
2. information sharing
   – e-mail, world wide web, Video Conference
3. improve reliability
4. improve power (per cost)
   – networked PC’s as powerful as a mainframe
5. killer apps
   - online games
   - videos on demand
6. scalable

Question 21

why do networks improve reliability

Answer 21

• redundancy (excess backup)

Question 22

business applications of network (2)

Answer 22

• uses client-server network architecture

- involves request (from client) and reply (from server)

Question 23

file sharing is

Answer 23

peer to peer

Question 24

subnet is

Answer 24

a collection of switching elements, minus the hosts