Chapter 1 Flashcards
Introduction
Communication network
Collection of hardware and software that enables users to share information.
Communication network definition expanded
Information is exchanged
Exchange occurs between users
In digital transmission, the information is converted into bits (1s and 0s)
At a receiver, information is reconstructed from bits
Digital transmission is used to minimise errors.
Switches
Switches control the sharing of links, which are network paths used and shared by users to get data.
Terminating nodes
Hardware destination of the data.
Business applications
Primary reason is resource sharing
Sharing of physical resources (printers, etc), and digital resources.
VPN (virtual private networks) are also used in businesses to make it more secure to go online. It gives the user an encrypted connection.
Home applications
Provide access to the internet
sharing a printer
streaming videos
Improve comfort by using the Internet of Things (IoT) devices
Mobile users
A device that can be moved without its function being effected.
Mobile devices are highly dependent on networks.
Social Issues
How the ability to access massive amounts of information affects everyday life.
How the existence of social media has effected society.
Protocol
An agreement between the communicating parties on how communication is to proceed.
Service
Is offered by one layer to other layers above or below it.
Common service primitives
LISTEN
CONNECT
ACCEPT
RECEIVE
SEND
DISCONNECT
Physical layer
Deals with the physical transmission of binary data over a medium
Data-link layer
Manages the flow of data sent to the physical layer, as well as the correctness of data from the physical layer.
Network layer
Ensures the data is transmitted through the most optimal route to the correct recipient in large networks.
Transport layer
Lowest “pure software” layer. Manages the data sent to the network layer as well as received.
Application layer
Interface between user applications and the rest of the network.
Connectionless
“Fire and forget” method. No attempt is made to check if the information is received correctly.
Connection oriented
Establish a communication channel before any information is transmitted.
