Bof Flashcards
ARPANET
first operational packet-switching networks
developed by ARPA (1960s)
Connects computers -> research institutions
allow communication + share resources within computers.
IMPs
Interface Message Processors
installed at each connected facility in the ARPANET
= intermediaries between network and»host»computer.
responsible for removing the burden of processing from the host computer
verify safe delivery of packets
retransmit them if necessary
control rate of data flow.
TCP/IP Model
network protocol suite
allow communication on the Internet through 4 layers: Application, Transport, Internet, and Network Access.
prioritized robustness/flexibility => enabling Internet to scale/adapt to different technologies and network sizes.
allowed for the creation of a loose arrangement of connected but autonomous networks
=> forming the foundation of the Internet.
Networking Infrastructure
cables
radio equipment
satellite connections
=> enable a network to transmit data between computers
=> allow for communication across different networks.
Open standards network
allow use of equipment/technologies from multiple suppliers
while maintaining strict central control
avoids monopolies in networking equipment
promotes competition
Gateway machines
devices that bridge various networks together
=> enable communication between different networks by streamlining the functions of the gateway computers + maintaining routing tables with the addresses of computers on their own local networks.
(-) Network adapter
converts signals into electrical signals for transmission and vice versa
interface between computers/devices and the network
MAC address -> unique address assigned to each network adapter, used for regulated access to the network medium and identifying stations connected to the same channel
(-) Hub
facilitates data sharing between computers within a network (central server)
used in star topology
(-) Switch
better version of hub
examines the destination address
redirects the packet to the destination alone
=> allowing for more effective bandwidth utilization
Intranet
personalized version of Internet
only accessible within an organization
protected by a firewall if connected to the internet
Extranet
partially accessible intranet
allows authorized outsiders to access certain parts of the intranet, with access controlled by a firewall
OSI model
conceptual framework
explain communication system into 7 layers
allows for easier troubleshooting, scalability, and interoperability
(-) Physical Layer:
transmission of raw bit over the physical medium (cables/wireless signals).
(-) Data Link Layer:
validity + integrity of data transmission between nodes
divides raw bits into frames
handles physical addressing, flow control, error notification, topology.
(-) Network Layer:
routing + addressing data
determines best path for data packets to reach their destination.
(-) Transport Layer:
reliable + transparent transfer of data
uses protocols like TCP/ UDP for transport.
(-) Session Layer:
establishes, manages, terminates connections between applications
synchronization + checkpointing of data exchange.
(-) Presentation Layer:
data representation
encryption
ensures that data is properly formatted/encrypted -> secure transmission.
(-) Application Layer:
interfaces a user with the network
provides services + protocols for applications to interact with the network.
Blockchain characteristics
Shared ledger -> everyone has a copy of the same transaction records
Blocks of Transactions -> transactions are grouped into blocks and added to the chain in chronological order
Highly Secure + Transparent -> difficult to change blocks
Verification by Consensus -> transactions verified/accepted by the network before being added to the chain
4 Linked Data Principles
Tim Berners-Lee 2007
(1) using URIs as names for things
(2) using HTTP URIs to look up those names
(3) providing useful information using RDF standards
(4) links to other URIs to discover more things
Web 3.0 (Semantic Web)
collaborative movement led by (W3C)
provide a common framework for sharing + reusing data across different applications, enterprises, and communities
understand + respond to complex human requests based on the meaning of the data
built on technologies like RDF and RDF Schema
aims to make the meaning of data explicit and structured
Web 4.0
next generation of the WWW
intelligent agent
can read and understand web content
making decisions and executing tasks
Web Browsers
software application
allows users to access + view web pages on the WWW
act as an interface between the user and the WWW
enable navigation, interaction with web content, and various tasks
Ex : Mosaic, Internet Explorer, Google Chrome, Safari
HTML
standard markup language used for creating web pages and applications
HTTP
protocol that allows for the retrieval and transfer of information on the WWW
URI
string of characters that identifies a resource on the internet
include URLs + URNs
