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Research Note Topic:
Research Note Description:
wide area network
is a computer network that spreads across a region, a whole country or even the whole world. WANs interconnect LANs located in any part of the world. It spans a large geographical area like a country or a continent. It contains a collection of machines called
that run user(i.e. application programs). The LANs are connected with the help of WAN backbones. Generally WANs use satellites as the primary transmission on media and, therefore, the transmission is comparatively costly. Where LAN market has grown at the rate of 175%, the WAN growth has been relatively slow at 4)%. The popular, WAN protocols are: X.25, Frame Relay, and ATM(asynchronous transmission mode). The protocols stated are explained briefly below:
This protocol is a low bandwidth transmission protocol with 50kbps data transfer rate. It was earlier used by most of the WANs.
The Frame Relay is a high bandwidth protocol with 56kbps to 45Mbps data transfer rate. In fact, this is a stream lined version of X.25 protocol that assumes reliable communication links. It is a very cost effective transmission protocol and is very popular within Networking companies.
It is an extremely fast transmission protocol with bandwidth as high as 622Mbps. It is also designed to handle integrated data, voice, and video transmission. This protocol is gaining popularity world wide because it can handle both video and multimedia applications. Example:
uses both X.25 and Frame Relay technology to connect the various LANs of its offices world over.
The popular WAN installations in India are Nicnet, I-Net, Calibnet, coalnet, ERNET(Education and Research Network), Sail net and Star net. The salient features of ERNET are given below: 1. This network is primarily meant for promotion of information exchange among the various educational and research institutes such as IITs, IISc, DOE etc. 2. Common services provided by this network are:
(i) file transfer
(ii) data bases access
The ERNET Architecture is shown below:
Prof. Ashay Dharwadker