SLR 11/ Networks

Question 1

Define Peer-to-Peer networks

Answer 1

Each PC on the network has equal responsibility​
No single point of failure​
PCs not reliant on each other for resources​
Generally easier to maintain and set up

Question 2

Define Client-Server networks

Answer 2

One central server controls the network​
Central point of failure​
Network access centrally controlled​
Generally more complex to manage​
Many tasks can be handled by the server

Question 3

Define Authentication

Answer 3

Require a username and password to log on​
Multiple credentials​
Smart cards​

Question 4

Define Proxies

Answer 4

Physical computers​
Placed between the network and outside world​
Traffic must pass through

Question 5

Define Firewalls

Answer 5

Software and hardware​
Isolate network traffic​
Configured to allow or deny traffic in or out​
Stateful packet inspection

Question 6

Define Encryption

Answer 6

Encrypts traffic so it can’t be read without being decrypted​. Data is encrypted and decrypted using a set of
keys.

Question 7

Name the 4 methods of securing a network

Answer 7

Authentication
Proxies
Firewalls
Encryption

Question 8

Factors for Dedicated Servers

Answer 8

There for Server farms in professional data centres.
Costly to set up and maintain.
Extremely reliable.
Low Latency
High performance

Question 9

Factors for Listen Servers

Answer 9

Half-way between dedicated client-server and peer-to-peer. One client acts as a temporary server.
Dependent on speed of host internet connection.
Host advantage requires lag compensation.
Host migration if host leaves.

Question 10

Factors for Peer-to-peer

Answer 10

All data is sent as raw streams to all other computers in the game.
No specialist infrastructure required.
Number of connections and players is limited.
Same latency for all players.

Question 11

What are Protocols

Answer 11

A protocol is a set of rules defining how two computers communicate with each other.
Protocols are standard so that all devices have a designated method of communicating
with each other, regardless of manufacturer.
HTTP and POP3 are types of Protocols.

Question 12

Name the Layers of the TCP/IP stack and protocol layering.

Answer 12

Stage 1 - Application Layer
Stage 2 - Transport Layer
Stage 3 - Network Layer
Stage 4 - Link Layer

Question 13

What is Stage1 - Application Layer

Answer 13

The application layer is based at the top of the stack. It specifies what
protocol needs to be used in order to relate the application that’s being sent

Question 14

What is Stage 2 - Transport Layer

Answer 14

The transport layer uses TCP to establish an end-to-end connection
between the source and recipient computer.
The transport layer splits data up into packets and labels these packets with
their packet number
The total number of packets the original data was split
up into and the port number being used for communication.

Question 15

What is Stage 3 - Network Layer

Answer 15

The network layer adds the source and destination IP addresses. The
combination of the IP address and the port number is called a socket
address

Question 16

What is Stage 4 - Link Layer

Answer 16

The link layer is the connection between the network devices, it adds the
MAC address identifying the Network Interface Cards of the source and
destination computers

Question 17

What is LAN

Answer 17

Local Area Network. A LAN is a network spread over a small geographical area. Hardware usually owned by the person/business

Question 18

What is WAN

Answer 18

Wide Area Network. a WAN is typically spread
over a large geographical area. Usually, a WAN will require extra telecommunication
hardware. Infrastructure used in WANs is owned by third-parties.

Question 19

What is the DNS

Answer 19

Domain Name Server (DNS) is the system used to name and organize internet
resources. It is a hierarchy, in which each smaller domain is separated from the larger
domain by a full stop.

Question 20

What is a Data Packet

Answer 20

Packets are segments of data

Question 21

Explain the process of a data packet.

Answer 21

1. Header. Contains the sender and recipient IP addresses
2. Protocols Being used. Allows the recipient to understand the packet
3. Order of packets. Packets reconstructed in order
4. Time to Live. Tells the packet when to expire so it doesn’t travel forever

Question 22

What is the Payload

Answer 22

Raw data to be transmitted

Question 23

What is Packet Switching

Answer 23

Packet switching is a method of communication in which data is communicated using
packets across a network. In this method of communication, packets are sent across the
most efficient route, which can vary for each packet.

Question 24

Advantages and Disadvantages of Packet Switching

Answer 24

Advantages: Multiple methods to ensure data arrives intact. Multiple routes can be used between
devices, so if one path breaks, another
can be used
Disadvantages: Time is spent deconstructing and
reconstructing the data packets. Must wait for all packets to arrive before
data can be received.

Question 25

What is Circuit Switching

Answer 25

Circuit switching is a method of communication where a direct link is created between two devices. This direct link is maintained for the duration of the entire conversation between devices. Circuit switching requires the two devices to transfer and receive data at the same rate.

Question 26

Advantages and Disadvantages of Circuit Switching.

Answer 26

Advantages: Data arrives in a logical order which results in a quicker reconstruction of the data. Enables two users to hold a call without delay in speech.
Disadvantages: Bandwidth is wasted during periods of
time in which no data is being sent. Devices must transfer and receive data at
the same rate. Using switches means electrical
interference may be produced which can
corrupt or destroy data.

Question 27

What are Proxy servers

Answer 27

A proxy server acts as an intermediary, collecting and sending data on behalf of the user.
There are several benefits of using proxies:
1. The privacy of the user is protected and they remain anonymous
2. The proxy server can cache frequently used website data making it faster to load
3. Proxies can reduce overall web traffic