A Computer Network or
simply a network refers to any number of independent computer systems that are
interconnected to make data exchange feasible. For this, in addition to a
physical connection, there must also be a logical connection between the
networked systems — the latter produced by specific network protocols, such as
the Transmission Control Protocol (TCP ). Even only two computers connected can
be considered as a network.
The networks are set up, in
particular, to transfer data from one system to another or to provide shared
resources such as servers, databases or a printer on the network. Depending on
the size and scope of the computer network, it is possible to differentiate and
categorize systems. The following are the main categories of computer networks:
Different Types of
Computer Networks
·
Personal
Area Network (PAN) or personal network
·
Local Area
Network (LAN) or Local Area Network
·
Metropolitan
Area Network (MAN) or Metropolitan Network
·
Wide Area
Network (WAN) or Wide Area Network
·
Global Area
Network (GAN) or global network
The physical connection that
connects these types of networks can be wired (wired) or made using wireless
technology. In many cases, physical communication networks form the basis of
several logical networks, called virtual private networks (VPNs ). These
utilize a standard physical transmission means, for example, an optical fiber
cable and, when transferring data, is assigned to logically different virtual
networks using VPN software creating a tunnel (or tunneling software ).
Each type of network has developed
for specific application areas — a network-based on own techniques and
standards, providing different benefits and limitations.
Personal Area Network (PAN)
To enable data exchange of modern
devices such as smartphones, tablets, laptops, or desktops, they can connect to
a suitable network. It can join in the form of a personal network or PAN (
Personal Area Network ), it is also called home network. Standard transmission
techniques are USB or FireWire. The Wireless Personal Area Network (WPAN))
relies on technologies like Bluetooth, USB wireless, INSTEON, IrDA, ZigBee or
Z-Wave. A personal wireless network that can make via Bluetooth is called
"Piconet." WPANs and PANs usually only cover a few meters and are not
suitable for connecting devices in different rooms or buildings.
In addition to the communication of
several devices with each other, a personal network also allows the connection
to other systems, usually more significant. We are talking in this case of an
Uplink or uplink. Due to the limited scope and relatively low rate of data
transfer, NAPs are mainly used to connect peripherals for recreational use.
Typical examples are wireless headphones, game consoles, and digital cameras. In
the context of the Internet of Things (idO), IoT Internet of Things), WPANs
used for communication, control, and monitoring of low data rate applications.
Protocols like INSTEON, Z-Wave, and ZigBee designed for home automation.
Local Area Network (LAN)
If multiple computers are to join
on a network, this is usually in the form of a Local Area Network (LAN ). Such
a network can connect two computers in a house or several hundred devices
within a company. But also networks in public institutions like administrations,
schools, or universities are generally implemented in the form of a LAN. A
widespread common standard for wired LANs is the Ethernet protocol. Other less
common and sometimes obsolete technologies are Arcnet, FDDI, and Token Ring.
The transmission of data is done electronically based on copper cables or via
fiber optic cables.
If more than two computers are
nested together in a local area network, additional components such as a hub,
bridge, or switch (network switch) are needed and then act as bridging elements
and distribution nodes. A LAN is designed to allow fast transfer of large
amounts of data. Depending on the structure of the network and the transmission
medium used, a data rate of 10 to 1000 Mbit / s is standard. Local networks
allow a comfortable exchange of information between the different devices
connected to the network. In the context of a business, it is common for many
work computers to share file servers, network printers, or applications on the
LAN.
Metropolitan Area Network (MAN)
A Metropolitan Area Network (MAN)
is a broadband telecommunication network that connects several LANs. These are
typically different branches of a company that connects to a MAN via leased
lines. High-performance routers and high-performance optical fiber connections
are used to provide a much higher data rate than the Internet. The speed of
transmission between two remote nodes is comparable to the communication in a
local network. As a metropolitan network, cable cities can integrate into
extensive area networks: Wide Area Networks (WANs)) and internationally at the
Global Area Networks (GAN ) level.
Wide Area Network (WAN)
While metropolitan networks connect
areas that are close to each other in rural or urban regions, extensive area
networks (WANs ) span massive geographical places across a country or region. A
continent for example. In principle, the number of local area networks or
computers connected to a vast area network is unlimited.
While local area networks (LANs)
and MANs can make due to the geographical proximity of connected computers or
networks based on Ethernet, WANs use techniques such as IP / MPLS
(Multiprotocol Label Switching), PDH ( Plesiochronous Digital Hierarchy), SDH
(Synchronous Digital Hierarchy), SONET (Synchronous Optical Network), ATM
(Asynchronous Transfer Mode) and still rarely the obsolete X.25.
Extended networks owned by an
organization or company and are therefore privately or rented. Also, ISPs use
WANs to connect local area networks of companies and customers to the Internet.
Global Area Network (GAN)
A global network like the Internet
is also called Globe Area Network (GAN ). The Internet is not the only computer
network of its kind. Internationally active companies also maintain isolated
networks that span multiple WANs and thereby connect corporate computers
worldwide. GANs use the fiber optic infrastructures of wide-area networks and
combine them with international submarine cables or satellite transmissions.
Virtual Private Network (VPN)
A
virtual private network (VPN) is a virtual communication network that uses the
infrastructure of a physical interface to logically connected computer systems.
It can be any network detailed above; however, the Internet is the most
commonly used means of transmission. It connects almost all computers around
the world and remains available for free as opposed to the private operation of
a MAN or WAN. The data transferred within a virtual tunnel built between a VPN
client and a VPN server.
No comments:
Post a Comment