Optical Ethernet







Introduction

 LAN  forms basis of all commercial,research,and data communication    networks.Recently an increase in applications demand significantly higher band width. Ethernet is an easy to understand and extremely cost-effective technology. For these reasons, 98% of local area network (LAN) connections are now Ethernet based.

                           To meet this,high speed LAN types have been developed ,including a number of variations of basic ethernetLANs.  CSMA/CD(carrier sense multiple access with collision detection) is used widely in wired LANs as a MAC(Medium Acess Control) method.      Transmission medium is coaxial cable (ether) up to 2.5km long,with repeaters at every 500meters.Upto 256 machines could be attached to the system via transceivers screwed onto the cable.The system ran at 2.94Mbps

WAN

                    Ethernet transport has not yet taken off in the long-haul network, but this is expected to change as 10-Gigabit Ethernet interfaces become available. Some of those are expected to operate at SONET OC–192 speeds and at the distances needed for long-haul networks. The distance limitations are not a serious concern because most long-haul networks use dense wavelength division multiplexing  (DWDM) systems to combine multiple circuits over a single fiber, each on its own wavelength, and these DWDM systems provide the long-haul capability themselves.    Still, wide-area Ethernet networks are expected to be implemented, the main reasons being speed, cost, and simplicity.

Future Expectations


                  Ethernet is (by a huge margin) the most successful networking technology ever. After all, 99 percent of all TCP/IP packets (including Internet traffic) traverse an Ethernet somewhere (and more likely five or six Ethernet LANs in the World Wide Web). And the future is even brighter! The Radiance Optical Ethernet System is a new breed of optical access and connectivity that provides a secure, yet manageable, Ethernet demarcation point between the service provider and business user


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