lecture 1 Flashcards
definition of networking
an interconnected collection of autonomous computers
meaning of interconnected
can exchange information via a medium
e.g. fiber, copper, wireless
meaning of autonomous
- no-master slave
- if master goes down, slave remains standing/working
meaning of a distributed system
the collection of independent computers appears to its users as a single coherent system Single Model
difference between a computer network and a distributed network/system
- distributed system: all systems appear as a SINGLE system
- network system: all machines, hardwares and softwares are transparent and visible (you can see all individual systems)
example of a distributed system
- World Wide Web
- 1 webpage
what is the internet
a global system of interconnected networks, using a standardized Internet Protocol suite for communication and sharing information
meaning of telecommunication
communication over a distance
meaning of telecommunication
communication over a distance
meaning of data communication
the exchange data between two devices via some form of transmission medium such as a wire cable
meaning of data communication
the exchange data between two devices via some form of transmission medium such as a wire cable
meaning of a network
a set of nodes connected by communication links
meaning of a node
any device that is capable of generating and receiving data
5 components of a data communication
- sender
- receiver
- medium
- data/message
- protocols
when do we care about delay (when do we need high latency)
and what do we sacrifice in turn
when it comes to things that are realtime
eg a live stream
- quality
when do we care about quality and what do we sacrifice in turn
when it comes to things that are sensitive
eg a bank transaction
- latency
telephone lines vs internet
similarity: connect machines together
differences:
- internet use packet switching
- telephone lines use circuit switching
components of a computer network
- hardware
- software
- protocols
- makes hardware convenient (OS)
two famous networking commands
- ping
- trace route
why are networks used by people
- advantages (5)
- resource sharing
– printers, terminals, special architectures - information sharing
– e-mail, world wide web, Video Conference - improve reliability
- improve power (per cost)
– networked PC’s as powerful as a mainframe - killer apps
- online games
- videos on demand - scalable
why do networks improve reliability
- redundancy (excess backup)
business applications of network (2)
- uses client-server network architecture
- involves request (from client) and reply (from server)
file sharing is
peer to peer
subnet is
a collection of switching elements, minus the hosts
