Topic 1- Overview Flashcards
Network
System for connecting computers, using a single transmission technology.
Internet
set of networks connected by routers that are
configured to pass traffic among any computers
attached to networks in the set.
First internet
APPANET
Military American network
*The main goal- sharing resources
*Allowed reliability (if one computer is down, the network is still able to function).
The Ethernet standard
Physical connection between computers and devices. Made the LAN (local area network) possible .
Economic impact
used in advertising, production, shipping, planning,billing, and accounting
Why CN is complicated (4 reasons)
*Diverse technologies, each has features that distinguish it from the others Multiple NW standards, some are incompatible Various commercial *NW products and services that use the technologies in unconventional ways
*Multiple technologies required to interconnect two or
more NW
*Many combinations of NW are possible!
NW Applications VS. Programming
Network applications: program that communicates
across a network (Email, file transfer, web browsing, social media)
Network programming: write codes for network
applications to communicate across a network
(Similar to conventional programming)
Data communication
study of low-level
technologies used to send information across a
medium like wire and radio wave
• Provides foundation of concepts on which
networking is built upon
Packet communication
a way to allow multiple senders to
transmit data over a shared network
• Divides data into small blocks call packets
• Each packets has an identification for the intended
recipient
Transmission Control Protocol (TCP) And IP
Transport layer protocol that receives data and divide them into smaller packets.
On the other hand, IP (internet protocol
) is a Network layer protocol that deals with the routing of the packets through the Internet.
ISP
An Internet Service Provider=
A vendor who offers Internet access for a fee.
*An ISP is considered public if any individual or organisations can use its services if they pay the subscription fee.
Private Network VS public Network
Private- Restricted to one group of users but can be leased from an ISP (enterprise level)
Public- a network owned by a ISP and offers
service to any individual or organisation that pays
the subscription fee (at home)
Private Network Types
*Consumer: smallest and least expensive private network
*Small Office/Home office (SOHO) : slightly larger than
consumer network
*Small-to-medium Business (SMB): larger than SOHO,
usually multiple offices in a building
*Large Enterprise: large network with multiple buildings
Interoperability for Communication
For Communication between entities, they must agree on the details
• Electrical voltage used to the format and meaning of
messages
• To ensure entities can interoperate (ability of two entities to communicate without misunderstanding)
rules for all aspects of communications are written down. These are called Communication protocol.
Networking Standards
De jure and De facto
Networking standards ensure interoperability
between product vendors
• de jure: if they have been produced or accepted by
a recognized standards body.
Hardware and communications standards are often
de jure, like Network routers
(ex. TCP)
• de facto: if they have not been accepted by a
recognized body but have gained widespread use by
market forces
Software standards are often de facto
(ex. iOS, android)
