Communication

Question 1

LAN

Answer 1

LAN - private network for a small geographic area. Has shared resources, it is scalable and many computers can be connected the LAN. A large LAN has a specialist server that carries out ONLY one role.

Question 2

WAN

Answer 2

Multiple LANS come together to make up a WAN networks connected to other networks which can communicate over a wide geographic area. Like towns, regions and globally. Uses telephone wires and satellite communications

Question 3

Client server model

Answer 3

at least one computer used to “serve” other computers are referred to as “clients” server provides services / applications etc. which may be requested by clients

Question 4

Peer to peer networking

Answer 4

All computers are of equal status Each computer provides access to resources and data // data is distributed Computers can communicate and share resource Each computer is responsible for its own security

Question 5

Thick clients

Answer 5

More extensive resources. Higher processing power, memory and data storage. Application software is installed locally.

Question 6

Thin clients

Answer 6

Limited resources with limited processing power, memory and data storage. server does all the work, the role of the client is to only provide the server with input.

Question 7

Bus topology

Answer 7

Each device is called a node, it has two terminators at the end to avoid bouncing of data. Data gets sent throughout the whole cable. Uses both twisted pair and coaxial cables.

Question 8

Star topology

Answer 8

Each node has a connection to a central device. The data transmission can be unicast, multicast or broadcast. It uses a central device to connect to the clients or devices.

Question 9

Mesh topology

Answer 9

Every node is connected to every node. Data transmission can be unicast, multicast or broadcast.

Question 10

CLOUDDD

Answer 10

Accessing a service/files/software on a remote server

Question 11

Public cloud

Answer 11

Computing services offered by 3rd party provider over the public
Internet open/available to anyone with the appropriate
equipment/software/credentials

Question 12

Private cloud

Answer 12

Computing services offered either over the Internet or a private internal
network Only available to select users not the general public. Private is a dedicated/bespoke system only accessible for/from the
organization

Question 13

Disadvantages of peer to peer

Answer 13

each computer is at risk from viruses from other computers
No central management of backup if the data from one computer is not backed up it is lost to all of them
No central management of files/software consistency may be difficult to maintain
In order to share files etc. all the computers involved need to be switched
on . may not be always available

Question 14

Twisted pair copper cables

Answer 14

Cancels out electromagnetic interference
Made up of two insulated copper wires. Used in LAN lowest data transfer, cheapest. Shielded - commercially used. Unshielded - residency.

Question 15

Coaxial cables

Answer 15

Used in bus networking for the ethernet. Electromagnetic interference from other metal objects will not affect the signals. Better data transfer, best jamming capacity.

Question 16

Fibre-optic cables

Answer 16

Made of glass, best data transfer. small signal. High resistance. Single - Light faster good for telecommunications.

Question 17

Hub

Answer 17

Connects devices from local area
takes any data packet sent to it and sends it to every computer
not secure
can be wired or wireless

Question 18

Switch

Answer 18

Similar to hub
sends it to the correct device once more smarter

Question 19

Repeaters

Answer 19

Boosts signals or enhances signals
to be used in a large distance
hubs that contains repeaters are known as repeating hubs. prevents dead spots - where wifi is not reached at a certain area

Question 20

Bridge

Answer 20

Connects one LAN to another LAN that uses the same protocol. they are often use to connect different part of LAN to function as a single LAN to prevent traffic and flooding

Question 21

Router

Answer 21

To receive packets from devices or the Internet
* To forward / route packets to the destination
* To find the destination of the packet
* To assign / allocate private IP addresses to devices on LAN

Question 22

Ethernet

Answer 22

Type of bus networking, uses the MAC address of a device rather than the IP as devices can share the same IP addresses if they are connected to different networks

Question 23

CSMA/CD

Answer 23

Ethernet uses Carrier Sense Multiple Access/Collision Detection (CSMA/CD)
A workstation / node (wishing to transmit) listens to the communication
channel data is only sent when the channel is free // … if channel is free data
is sent Because there is more than one computer connected to the same
transmission medium two workstations can start to transmit at the same time, causing a
collision If a collision happens, the workstations send a (jamming) signal / abort
transmission and each waits a random amount of time before attempting to resend

Question 24

Bit streaming

Answer 24

sequence of digital signals / bits
– over a communication path Internet
– transfer of data at high speed
– requires fast broadband connection
– requires some form of buffering this makes stream run more smoothly
– bits arrive in the same order as sent

Question 25

DNS

Answer 25

WWW is a collection of interlinked, hypertext documents/webpages/multimedia resources (accessed via the Internet) //WWW is content from web servers organized as
web pages
* Internet is the global connection of interconnected computer networks
* The Internet uses TCP/IP protocol / WWW uses http protocols to transmit data

Question 26

Gateways

Answer 26

Routers can act as gateways but gateways cannot act like routers. Gateways cannot move packets. It is a device that helps you get connected to the internet.
It can connect two dissimilar protocols

Question 27

Modems

Answer 27

Converts analogue signals to digital signals, inbuilt and cannot be seen. It is a part of the router now.

Question 28

NIC

Answer 28

Receives analogue radio waves convert them to digital / binary
Checks incoming transmissions for correct MAC / IP address ignore transmissions not intended for it
Takes digital/binary input and converts to analogue waves sends the radio waves via the antenna
Encrypts / encodes the data
Decrypts / decodes the data

Question 29

WNIC

Answer 29

Hardware component that allows a device to connect to
a wireless network // Provides a MAC address to the
device to identify it on the wireless network

Question 30

WAP

Answer 30

Hardware component that provides radio
communication from the central device to nodes on the
network

Question 31

IP v 4 Types

Answer 31

Network ID
Class A - Byte 1
Class B - Byte 1 and byte 2
Class C - Byte 1, byte 2 and byte 3
Host ID
Class A - Byte 2, byte 3 and byte 4
Class B - Byte 3 and byte 4
Class C - Byte 4

Question 32

Public IP address

Answer 32

It is visible to any device on the internet

Question 33

Private IP address

Answer 33

It is only visible to devices within the Local
Area Network (LAN)

Question 34

Dynamic IP address

Answer 34

A new one is reallocated each time a device
connects to the internet

Question 35

Static IP address

Answer 35

It does not change each time a device
connects to the internet