Networks Flashcards

Question

What are the advantages of bus topology?

Answer 1

Easy and inexpensive to install - less cabling than in a star topology network Easy to add new computers

Answer 2

If the main cable fails then the whole network goes down Cable failures are hard to isolate because it affects all of the components attached Performance slows down as the amount of traffic increases

Answer 3

Ring Network: Computers are connected to adjacent computers in a ring. Computers take it in turns to transmit, controlled by passing a token around the ring. Computers can only transmit when they have the token.

Answer 4

Advantages: Not dependent on a central computer like the star network Token passing protocol is simple and therefore reliable Consistent performance even when there is a lot Of traffic

Answer 5

Disadvantages: A Single node or link failure and the network is disrupted

Answer 6

Star Network: All of the computers have their own cable that connects them to a central computer. The central computer controls the network. This is usually a server, where shared resources are stored.

Answer 7

Advantages: If one cable fails only one station is affected rather than the whole network Consistent performance even when network is heavily used Easy to add new computers More secure — messages from a computer go directly to the centre

Answer 8

Disadvantages: Can be costly to install because there is a lot of cabling Dependence on central computer, if it fails whole network goes down

Answer 9

``` At least three PCs One shared device i.e Printer Servers i.e. Email, File, Internet Router connecting to the Internet Any topology specific devices labelled Devices need a NIC ```

Answer 10

Two basic goals: Stop unauthorised people accessing resources Ensure authorised people can access all the resources they need

Answer 11

When the user is required to prove they are an authorised user. Normally done with a username and password. They are checked in the central database

Answer 12

Protects data as it makes it difficult for others to read or alter it Typically used for online shopping to keep payment details safe Terminology: Plaintext – original message Ciphertext – encrypted message Encryption – process of converting from plaintext to ciphertext Decryption – the process of converting from ciphertext to plaintext Key – a sequence of numbers used to encrypt/decrypt Algorithm – the method used for encrypting

Answer 13

Designed to prevent unwanted traffic from gaining access to a LAN Unauthorised users are blocked by the firewall Certain ports can be closed to prevent specific types of packets from entering

Answer 14

``` Generally used on a wireless network A list of allowed MAC addresses can be set up under the MAC address filtering option Weakness: Only identifies permitted device Doesn’t identify the individual user ```

Answer 15

In order to provide a high level of security a combination of the methods discussed would need to implemented

Answer 16

Application Transport Network Link It consists of a number of different protocols across the four layers, that collectively allow data packets to be sent and received.

Answer 17

A complex problem can be broken into smaller manageable pieces (decomposition) changes in one layer do not impact on other layers It provides a universal standard for hardware and software manufacturers to follow Each layer carries out distinct functions and therefore avoids repetition of tasks

Answer 18

Is where applications such as web browsers and email clients operate Data being sent is encoded so that it will be understood by the recipient An appropriate header is added, according to the protocol being used, before passing the data to the transport layer

Answer 19

FTP HTTP HTTPS This provides a level of encryption to keep personal information secure, such as payment details SMTP POP IMAP

Answer 20

Internet Message Access Protocol Similar to POP but messages do not have to be downloaded as they can be read and stored on the server. This is better for users with multiple devices as they can be accessed from all devices.

Answer 21

Sets up the communication between the hosts and agrees settings such as language and packet size Divides data received from Application layer into packets of the correct size and adds packet information such as packet number and total number of packets Checks that packets arrive safely (TCP) and sends acknowledgements when receiving data

Answer 22

TCP UDP Alternative to TCP but has no error checking or correction Maintains an open connection between sender and receiver for the duration of the communication Often used for online gaming and live broadcasting where speed is desirable and error correction is not necessary

Answer 23

Addresses and packages data for transmission | Attaches source and destination IP address which are used to route the packet across the Internet

Answer 24

Concerned with transmitting the data through the local network using the protocols of the specific network i.e. Ethernet The MAC addresses of the sender and recipient are attached to the data allowing the packet to be directed to a specific device on a local network This is where network hardware is located, such as the NIC, and the operating system device drivers

Answer 25

Ethernet Refers to a suite of networking protocols used in LANs Describes how devices should format data ready for transmission between computers on the same network Nodes wait until the connection is quiet before attempting to transmit Two nodes attempting to transmit simultaneously will stop and wait a random period before reattempting

Networks Flashcards

(50 cards)