Networkimg

Question 1

CIrcuit switch network

Answer 1

A route from source to destination is reserved.
Data follows the same route to its destination
The returning data follows the same route back to the source

Question 2

Packet-switched network

Answer 2

The data to be sent is broken up into packets

Packet headers determine the destination and method of transmission

Question 3

Properties of CIrcuit switch and Packet-switched network

3

Answer 3

dedicated/established route
Each packet take same/different route
Packets arrive in same/different order

Question 4

Advantage of circuit switch

3

Answer 4

Dedicated path for transmission, with guaranteed bandwidth

Information is sent in a continuous stream; there is no need for intermediate nodes to store and retransmit information (reduce data corruption)

low overhead required for transmission

Question 5

Advantage of packet switch

3

Answer 5

Only the sender needs to be ready before transmission begins

If any segment of the network is disrupted, data packets can be routed around the disruption through other segments of the network

Congested segments can be bypassed if other segments are available, enabling greater utilisation of the network

Question 6

Client

Answer 6

Computers/ program used by the end-user

which sends requests to the server and receives a response

Question 7

Server

Answer 7

Servers refer to dedicated computers or software running on a computer
which receives requests from a server and sends a response

Question 8

Peer to peer

Answer 8

In the peer-to-peer model of communication:
All computers may initiate communication by sending a request, or responding to a request.
There is no central server which contains all information

Question 9

Server client vs peer to peer

Answer 9

dedicated servers vs no dedicated server
expensive to build and maintain centralised server

Data is centralised and easier to control
Easier to ensure security of data since only server needs to be secure

Question 10

Port numbers

Answer 10

The OS assigns each application a random (internal) port number, so that data packets can be passed back to the correct application
there are 2^16 port numbers
0 to 2^10-1
2^10 to 2^15 + 2^14 -1
2^15 + 2^14 to 2^16

Question 11

IP addresses

Answer 11

4 numbers of 2^8 -1

127...* local host

Question 12

MAC addresses

Answer 12

Each NIC is uniquely identified by a media access control (MAC) address, so that data packets from them can be differentiated

Question 13

Application layer purpose

Answer 13

interacts with end user, create/format the data package

Question 14

Transport layer purpose + contain

Answer 14

establish connection between applications of the sender and the receiver

determine how data is sent and divide data into packets
ensure data is snet to correct programme in correct sequence

TCP/UDP header containing source and destination port number

Question 15

Internet layer purpose + contain

Answer 15

find the best route to deliver the data package

identify other computers and itself allowing data routing to be used

IP header containing
source and destination IP address

Question 16

Link layer purpose + contain

Answer 16

Transform data package to electrical signals or radio waves and transmit to the physical devices

Frame header containing sauce and destination MAC addresses

Question 17

TCP vs UDP

Answer 17

Reliable
Ordered
Streaming

TCP is slower UDP is lossy

Question 18

Web app vs native

5

Answer 18

Update
Location
Platform
Security
Internet

Question 19

Well-known ports

Answer 19

0 to 2^10-1

Used by system processes that provide widely used types of network services

Question 20

Registered ports

Answer 20

2^10 to 2^15 + 2^14 -1

Assigned by the Internet Assigned Numbers Authority (IANA) by request

Question 21

Dynamic/ephemeral ports

Answer 21

2^15 + 2^14 to 2^16
Cannot be registered with IANA and may be used for any purpose
(usually temporary)