Appendix A - Ethernet Technology
D-Link Web Smart Switch User Manual
Appendix A - Ethernet Technology
This chapter provides some background information about Ethernet/Fast Ethernet/Gigabit Ethernet switching
technology.
Gigabit Ethernet Technology
Gigabit Ethernet is an extension of IEEE 802.3 Ethernet utilizing the same packet structure, format, and
support for CSMA/CD protocol, full duplex, and management objects, but with a tenfold increase in
theoretical throughput of over 100-Mbps Fast Ethernet and a hundredfold increase over 10-Mbps Ethernet.
Since it is compatible with all 10-Mbps and 100-Mbps Ethernet environments, Gigabit Ethernet provides a
straightforward upgrade without wasting existing investments in hardware, software, or trained personnel.
The increased speed and extra bandwidth offered by Gigabit Ethernet is essential to help solving network
bottlenecks that frequently develop as more advanced computer users and newer applications continue to
demand greater network resources. Upgrading key components, such as backbone connections and servers
to Gigabit Ethernet technology can greatly improve network response times as well as significantly speed up
the traffic between subnets.
Gigabit Ethernet enables fast optical fiber connections to support video conferencing, complex imaging, and
similar data-intensive applications. Likewise, since data transfers occur 10 times faster than Fast Ethernet,
servers outfitted with Gigabit Ethernet NIC’s are able to perform 10 times the number of operations in the
same amount of time.
In addition, the phenomenal bandwidth delivered by Gigabit Ethernet is the most cost-effective method to
take advantage of today and tomorrow’s rapidly improving switching and routing internetworking
technologies. And with expected advances in the coming years in silicon technology and digital signal
processing that will enable Gigabit Ethernet to eventually operate over unshielded twisted-pair (UTP) cabling,
outfitting your network with a powerful 1000-Mbps-capable backbone/server connection which will create a
flexible foundation for the next generation of network technology products.
Fast Ethernet Technology
The growing importance of LANs and the increasing complexity of desktop computing applications are
fueling the need for high performance networks. A number of high-speed LAN technologies have been
proposed to provide greater bandwidth and improve client/server response times. Among them, 100BASE-T
(Fast Ethernet) provides a non-disruptive, smooth evolution from the current 10BASE-T technology. The
non-disruptive and smooth evolution nature, and the dominating potential market base, virtually guarantees
cost-effective and high performance Fast Ethernet solutions.
100Mbps Fast Ethernet is a standard specified by the IEEE 802.3 LAN committee. It is an extension of the
10Mbps Ethernet standard with the ability to transmit and receive data at 100Mbps, while maintaining the
CSMA/CD Ethernet protocol. Since the 100Mbps Fast Ethernet is compatible with all other 10Mbps Ethernet
environments, it provides a straightforward upgrade and utilizes existing investments in hardware, software,
and personnel training.
Switching Technology
Another approach to push beyond the limits of Ethernet technology is the development of switching
technology. A switch bridges Ethernet packets at the MAC address level of the Ethernet protocol transmitting
among connected Ethernet or Fast Ethernet LAN segments.
Switching is a cost-effective way of increasing the total network capacity available to users on a local area
network. A switch increases capacity and decreases network loading by dividing a local area network into
different segments which won’t compete with each other for network transmission capacity.
The switch acts as a high-speed selective bridge between the individual segments. The switch, without
interfering with any other segments, automatically forwards traffic that needs to go from one segment to
another. By doing this the total network capacity is multiplied, while still maintaining the same network
cabling and adapter cards.
Power over Ethernet (PoE)
Power over Ethernet (PoE) integrates power and data onto one single cabling infrastructure, eliminating the
need to have AC power available at all locations.
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