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History of computer networks

Computer network

Computer network is composed of multiple connected computers that communicate over a wired or wireless medium to share data and other resources.

Network data protocols are used to communicate on the network between computers.

The size and scalability of any computer network are determined both by the physical medium of communication and by the software controlling the communication (i.e., the protocols).

The field of computer networking and today's Internet trace their beginnings back to the early 1960s, a time at which the telephone network was the world's dominant communication network. The global Internet's origin was the Advanced Research Projects Agency Network (ARPANET) of the U.S. Department of Defense in 1969 Nowadays, computer networks are developed rapidly

Classification of computer networks

Networks can be categorized in several different ways, for example,

  • By network layer
  • By scale
  • By connection method
  • By functional relationship
  • By network topology
  • By protocol

Classification by scale

A Local Area Network (LAN) is a group of computers and associated devices that share a common communications line and typically share the resources of a single processor or server within a small geographic area

A Wide Area Network (WAN) is a computer network that spans a relatively large geographical area (diameter of about 200 km)

GAN (Global Area Network) A network spanning a between geographically distinct cities

Classification by functional relationship

Server based (client/server): Computers set up to be primary providers of services such as file service or mail service.

The computers providing the service are called servers

The computers that request and use the service are called client computers.

Peer-to-peer

Various computers on the network can act both as clients and servers.

Example Many Microsoft Windows based computers allow file and print sharing.

Many networks are combination peer-to-peer and server based networks.

Major components of a computer network

A computer network possibly includes :

  • Computers: critical elements of any computer network. They can be considered nodes
  • A network card, NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network.
  • Network media (sometimes referred to as networked media) refers to media mainly used in computer networks : cable, telephone line or wireless.
  • Network connection equipments : HUB, SWITCH, ROUTER,etc.
  • Network Operating System (NOS) is an operating system that includes special functions for connecting computers and devices into a local-area network (LAN) or Inter-networking. Some popular NOSs for DOS and Windows systems include Novell NetWare, Windows NT and 2000, Sun Solaris and IBM OS/2.
  • Network software.
  • Network services, for example email.

Network topology

Network topology is the arrangement or mapping of the elements (links, nodes, etc.) of a network, especially the physical (real) and logical (virtual) interconnections between nodes .

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Introduction to computer science. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10776/1.1
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