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Data Communication & networking

This blog is for undergraduate/graduate students who require some basic information about their subjects or any other topic related to data communication.
Showing posts with label WAN. Show all posts
Showing posts with label WAN. Show all posts

Monday, 28 March 2011

WAN (Wide Area Network)

WAN (WIDE AREA NETWORK):
Wide Area Network is a computer network that covers a broad area i.e. any network whose communications links cross metropolitan, regional or national boundaries.
For transmission of data beyond local area communication is typically achieved throught a network of intermediate switching nodes. The purpose of switching nodes is to provide a switching facility that will move the data from node to node until it reaches to its destination.

Network Services Available For MAN & WAN:
1- Dialed Circuit Services: There services includes direct dialing and wide area telephone services.
2- DedicatedCircuit Services: It includes voice-grade circuits wideband analog services, T-carrier circuits & synchronous Optical Network (SONET).
3- Circuit Switched Services: it includes Integrated Service Digital Network (ISDN).
4- PacketSwitched Services: It includes X.25, Frame Relay, ATM, SMDS and Ethernet-IP.

TYPES OF WAN:
Following technologies are used in wide area switched networks,
(1) Circuit Switching (2) Packet Switching (3) Message Switching.
  • Circuit Switching: Requires a dedicated communication path for duration of transmission; wastes bandwidth, but minimizes delays.
  • Message Switching: Entire path is not dedicated, but long delays result from intermediate storage and repetition of message.
  • Packet Switching: Specialized message switching, with very little delay.