Monday, September 3, 2001		On Hardware

LAN cards make networking possible
Jasjot Singh Narula

COMPUTERS have revolutionised corporate offices, government and private business establishments. Modern offices no longer rely on a battery of cabinets containing accounting, personal, or marketing data to provide the information. Piles of files are being edged out by computers.

When Alexander Graham Bell invented telephone, it was a new concept of electronic communication and now computer technology has given a new dimension to sharing and accessing information and data.

In today’s environment success comes through reliable and effective source of medium that is network. The major breakthrough in communication is the Internet that had broken all barriers of human interactions.

Hundreds of people can share information and access the data in an office or outside it, thanks to networking, which is Internet and Intranet. When two or more computers are electronically connected for the purpose of exchange of information, networking is said to have been done.

Likewise, Intranet is a communication and sharing of data, which can be classified into two categories — LAN and WAN (Local Area Networking and Wide Area Networking, respectively).

Local Area Networking: This is a local network for inter-computer communication or data communication, which is geographically, limited allowing easy interconnection of terminals, microprocessors and computers within the office or adjacent building.

Local Area Network (LAN) or Ethernet network first came to existence in 1976 invented by Bob Metcalfe and Boggs of Xerox PARC (Palo Alto Research Centre).

In a layman’s language, it is that set-up where many computers can communicate and share data, specifically close to each other. For example we may have a computer (A) called server and B to Z are clients or workstations. The clients or workstations access information or data from the server A. So this A server may be a file server or print sever. File server stores data or information and print server used to share printers among the user of a LAN.

There are many devices involved to make the communication or networking possible that is in the form of hardware and software.

LAN component is determined on the topology, that is physical organisation or layout scheme. Actually it describes the arrangement of the cabling. There are three basic topologies — star, ring and bus.

We may have three kind of cable that can be used for connecting network component — Coaxial, Unshielded twisted Pair (UTP), Fibre optic. Coaxial cable is obsolete now. UTP cable is widely used because of the higher data transfer rate and it being economically viable. Fibre optic is expensive but is the latest. It comprises of insulated, glass or plastic thread transmits signals by light pulses.

Thirdly, the most important part is the Network Interface Card (NIC) or Ethernet card, also known as the LAN card. It is a circuit board that fits on the expansion slot of the motherboard. These cards allow a PC to have a dedicated connection to the LAN to transmit data back and forth to and from a server or other workstations.

Nowadays, the standard for the NIC is a PCI 10/100 MBPS (Mega bits per second) auto-sensing card. The auto sensing capability allows the NIC to detect what kind of network infrastructure it is connected to and data transmission at that speed. There is another device that acts as a bridge in a network known as Hub. Its function is to take the incoming signals and amplifying them without modifying its shape and putting the signal back on the media.

Protocols

If all these devices are configured properly till the end, the network is still not up without the protocols. Protocols refer to a set of rules that govern communications. Protocols act as a communicator within the computers. Like TCP/IP, i.e. Transmission Control Protocol and Internet Protocol

Meanwhile, Wide Area Networking is a communication network, which connects a smaller number of devices that can be many miles away, such as telephone lines, satellite dishes, or radio waves. In comparison, LAN is much faster and reliable than WAN.