SLR 11 & 12 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is a network

A

two or more computers connected together with the ability to transmit data between each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

WHt are the two main types of network

A

local area network (LAN), wide area network (WAN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is LAN

A

a network which is spread over a small geographical area, e.g. a school.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is WAN

A

a network which is spread over a large geographical area, e.g. large corporations with several offices.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the two types of network topology

A

physical topology, logical topology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is physical topology

A

the physical layout of the wires and components which form the network (e.g. bus, star, mesh)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is logical topology

A

the layout which shows how data flows in a network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is physical bus topology

A

all the devices are connected to a backbone cable, which is connected at the ends to terminators.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are advantages and disadvantages of bus topology

A

Adv.: inexpensive, no additional hardware.
Disadv.: if backbone fails whole network fails, as traffic increases performance decreases, all conputers can see data transmission.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is physical star topology

A

using a central node (often a switch) that all machines are connected to, to direct data through a network.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are advantages and disadvantages of star topology

A

adv.: consistent performance, if one cable fails only one terminal is affected, transmits data faster, easy to add new stations, no data collisions
disadv.: expensive, if central switch fails whole network fails

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is physical mesh topology

A

every node connected to every other node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are advantages and disadvantages of mesh topology

A

adv.: if using wireless network no cabling cost, nodes automatically incorporated, no central switch.
disadv.: if wired lots of cable cost, difficult to maintain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a protocol

A

a set of rules defining how two computers communicate with each other. they are standard so all devices have designated method of communicating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are examples of commonly used protocols

A

HTTP (Hyper-Text Transfer Protocol), TCP/IP (Transmission Control Protocol/Internet Protocol), POP3 (Post Office Protocol), IMAP (Internet Message Access Protocol), FTP (File Transfer Protocol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the internet

A

a network of networks which allows computers on opposite sides of the globe to communicate with each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the TCP/IP

A

A stack of networking protocols that work together passing packets during communication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the layers of the TCP/IP stack

A

Application layer, transport layer, network layer, link layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the application layer of the TCP/IP stack

A

At the top of the stack, specifies what protocol needs to be used in order to relate the application that’s being sent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the transport layer of the TCP/IP stack

A

Used TCP to establish end-to-end connection between source and recipient, splits data into packets and labels packets with packet number. If any packets get lost, transport layer requests retransmission of these lost packets

21
Q

what is the network layer of the TCP/IP stack

A

adds the source and destination IP addresses. routers operate on the network layer and the router is what used the IP addresses to forward the packets, the dockets are then used to specify which device the packets must be sent to and the application being used on that device.

22
Q

WHat is the link layer of the TCP/IP stack

A

connection between network devices, it adds the MAC address identifying the Network Interface Cards of the course and destination computers.

23
Q

What is a DNS

A

Domain name system is system used to name and organise internet resources.

24
Q

What are data packets

A

segments of data containing various information.

25
Q

what information does data packets contain

A

Header: Sender & recipient IP addresses; the protocol being used; the order of the packets; the Time To Live (TTL) / Hop Limit.

Payload: Raw data to be transmitted

Trailer: Checksum (or cyclic redundancy check)

26
Q

Why are the sender and recipient IP Addresses included in data packets

A

they act like a postcode, allowing the packet to be delivered to the correct destination and enabling the recipient device to trace where the packet came from.

27
Q

why is the protocol being used contained in data packets

A

the protocol allows the recipient computer to understand hoe to interpret the packet

28
Q

why is the order of packets included in data packets

A

Upon arriving at the recipient device, packets are reconstructed in the appropriate order as specified in the header.

29
Q

why is the Time To Live/Hop Limit included in data packets

A

tells the packet when to expire so that it does not travel forever

30
Q

What are the two techniques used when networks exchange data

A

circuit switching and packet switching

31
Q

what is packet switching

A

method of communication in which data is communicated using packets across a network

32
Q

what are adv and disadvantages of packet switching

A

adv.: multiple methods to ensure data arrives intact, multiple routes can be used between devices, packets can be transferred over large networks
disadv.: time is spent de- and reconstructing data packets, must wait until all packets arrive before data can be received.

33
Q

what is circuit switching

A

direct link s created between two devices. the link is maintaned for the duration of the conversation between devices. requires two devices to transfer and receive data at the same rate

34
Q

what are adv. and disadv. of circuit switching

A

adv.: data arrives in logical order which results in quicker reconstruction of data, enables two users to hold a call without delay
disadv.: bandwidth wasted during periods of time when no data is sent, devices must transfer and receive data at the same rate, electrical interference may be produced which can corrupt or destroy data, ties up sections of the network which cannot be used by others neil transmission is complet.

35
Q

what is a firewall

A

a device designed to prevent unauthorised access to a network. it consists of two network interface cards (NICs) between the user and the internet. the firewall passes the packets between these two NICs and compares them against a set of rules sent by the firewall software.

36
Q

what is packet filtering/static filtering

A

limits network access in accordance with administrator rules and policies. it works by examining source IP, destination IP, and the protocols being used as well as the ports being requested.

37
Q

what two thing can happen when access is denied by a firewall

A

the packet can either be dropped or rejected. a rejected packet sends an alert to a sender to notify them of the error whereas a dropped packet will not

38
Q

what is a proxy server

A

acts as an intermediary, collecting and sending data on behalf of the user. there are several benefits of using proxies.

39
Q

what are the benefits of using proxies

A

privacy of user is protected, server can cache frequently used website data making it faster to load, can reduce web traffic, can be used to prevent access to sensitive or irrelevant content at work/school

40
Q

what is encryption

A

a way of keeping data secure when transmitting data over the internet. it makes data unreadable if it is intercepted.

41
Q

what is a network interface card

A

NIC is a card required to connect a device to a network. usually built into the device and assigns a unique media access control (MAC) address to each device.

42
Q

what is a MAC address

A

a 48-bit value code into the device and usually written as a twelve digit hexadecimal number

43
Q

what is a switch

A

a device used to direct the flow of data across a network

44
Q

what is a WAP

A

WIreless Access Point, a device to connect to a network, it is more commonly combined with a router to enable internet access.

45
Q

what is a router

A

used to connect two or more network together. allows private, home networks to connect to the internet

46
Q

what is a gateway

A

used when protocols are not the same between networks. translates protocols so that networks can communicate with each other. they work by removing the header from packets before adding the data to packets using the new protocol

47
Q

what is a client-server network

A

network consisting of terminals (clients) connected to a server

48
Q

what is a server

A

a powerful central computer. holds all the important information and resources and has a greater processesing power