Dcn(data communication and computer network)

Dcn(data communication and computer network)

• 1.
  Data communications refersto the transmission of this digital data between two or more computers and a computer network or data network is a telecommunications network that allows computers to exchange data. The physical connection between networked computing devices is established using either cable media or wireless media. The best-known computer network is the Internet.
• 2.
   Basic computerconcepts like what is keyboard, mouse, monitor, input, putput, primary memory and secondary memory etc.
• 3.
   A systemof interconnected computers and computerized peripherals such as printers is called computer network. This interconnection among computers facilitates information sharing among them. Computers may connect to each other by either wired or wireless media.
• 4.
   Computer networksare classified based on various factors.They includes:  Geographical span  Inter-connectivity  Administration  Architecture
• 5.
   It maybe spanned across your table, among Bluetooth enabled devices,. Ranging not more than few meters.  It may be spanned across a whole building, including intermediate devices to connect all floors.  It may be spanned across a whole city.
• 6.
   Components ofa network can be connected to each other differently in some fashion. By connectedness we mean either logically , physically , or both ways.  Every single device can be connected to every other device on network, making the network mesh.  All devices can be connected to a single medium but geographically disconnected, created bus like structure.  Each device is connected to its left and right peers only, creating linear structure.  All devices connected together with a single device, creating star like structure.
• 7.
   Ethernet isa widely deployed LAN technology.This technology was invented by Bob Metcalfe and D.R. Boggs in the year 1970. It was standardized in IEEE 802.3 in 1980.
• 8.
   From anadministrator’s point of view, a network can be private network which belongs a single autonomous system and cannot be accessed outside its physical or logical domain. A network can be public which is accessed by all.  Network Architecture  Computer networks can be discriminated into various types such as Client-Server,peer-to- peer or hybrid, depending upon its architecture.
• 9.
   A PersonalArea Network (PAN) is smallest network which is very personal to a user. This may include Bluetooth enabled devices or infra-red enabled devices. PAN has connectivity range up to 10 meters. PAN may include wireless computer keyboard and mouse, Bluetooth enabled headphones, wireless printers and TV remotes.
• 10.
   A localarea network (LAN) is a group of computers and associated devices that share a common communications line or wireless link to a server. Typically, a LAN encompasses computers and peripherals connected to a server within a distinct geographic area such as an office or a commercial establishment.
• 12.
   A metropolitanarea network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN).
• 14.
   The WideArea Network (WAN) covers a wide area which may span across provinces and even a whole country.  Generally, telecommunication networks are Wide Area Network. These networks provide connectivity to MANs and LANs. Since they are equipped with very high speed backbone, WANs use very expensive network equipment.