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
Ø Optical Ethernet Today
Ø Recent Trends
Ø Future Expectations
Optical Ethernet is the technology that extends Ethernet beyond the local-area network (LAN) and into metropolitan-area networks (MANs) and wide-area networks (WANs). While Ethernet LANs are almost exclusively used within the enterprise, optical Ethernet technology can be used as a service provider offering. Key components of Optical Ethernet are the abilities to segregate traffic of different users and to deliver the particular service level each user purchases
They combine the flexibility, simplicity and cost effectiveness of Ethernet with the reliability, speed and reach of optics to allow users to extend their LAN environment across the MAN and WAN.
Beyond 10 Gigabits
Just as the growth of 10-Megabit Ethernet led to the need for 100-Megabit Fast Ethernet, and just as the growth of Fast Ethernet led to the need for Gigabit Ethernet, the growth of Gigabit Ethernet is now driving the market to 10-Gigabit Ethernet. This trend is not likely to stop anytime soon. Servers—whether Web servers, file servers, e-commerce servers, or others—must have greater bandwidth than the customers they serve, otherwise, those customers will feel frustrated with inadequate performance and possibly go elsewhere for service. The best example is Web servers.
If the average Web browser is using a 56k modem, a server on a T1 line can simultaneously handle approximately 30 customers. But the broadband movement has already started, and millions of consumers are now accessing the Internet from DSL and cable networks. These consumers access the Internet at speeds up to 10-Megabit Ethernet (typical connectivity for a cable-modem service), and for them, a service provider limited to a T1 line is already unacceptably slow.