N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 7 - LAN, WAN, VPN, WLAN, MAN, FDDI and Optical MANS                                                        Slide 3 of 45 _________________                                                                                  __________

                                                What is a LAN ?

          A Local Area Network (LAN) is a methodology to connect devices, such as
         computers, printers,  servers, to  transmit data  within a limited distance. 

                                    Distributed Computing

                                    Sharing Expensive Devices

                                    Inexpensive Computing

                                    A Compromise between Long Distances
                                      and Wide Bandwidths

_________________                                                                                  __________

Historically LANs have evolved from the centralized data processing where economics suggested that relatively expensive devices like storage devices and printers should be shared by multiple computers. LANs have evolved in response to the emergence of low-cost computing and its need for high-cost peripherals.

Centralized computing required expensive digital communications facilities. The communications facilities offered limited bandwidth whereas the LAN concept offered much higher data transfers. A typical LAN is a compromise between long distances and wide bandwidths.

Now LAN is facing challenges from new technologies like ATM, IP and SONET.