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
CONTENTS
Ø Introduction
Ø Technology
Ø History
Ø Optical Ethernet Today
Ø Recent Trends
Ø Future Expectations
Definition
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.
0 comments:
Post a Comment