D-Link TM DES-6500, Manual

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DES-6500 Chassis-based Layer 3 Ethernet Switch Manual
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Ethernet Technology
Fast Ethernet
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 are proposed to provide greater bandwidth and
improve client/server response times. Among them, Fast Ethernet, or 100BASE-T, provides a non-disruptive, smooth
evolution from 10BASE-T technology.
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 Carrier Sense Multiple
Access with Collision Detection (CSMA/CD) Ethernet protocol.
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, flow control, and management objects, but with a tenfold increase in theoretical
throughput over 100Mbps Fast Ethernet and a one hundred-fold increase over 10Mbps Ethernet. Since it is compatible with
all 10Mbps and 100Mbps Ethernet environments, Gigabit Ethernet provides a straightforward upgrade without wasting a
company's existing investment in hardware, software, and trained personnel.
The increased speed and extra bandwidth offered by Gigabit Ethernet are essential to coping with the network bottlenecks
that frequently develop as computers and their busses get faster and more users use applications that generate more traffic.
Upgrading key components, such as your backbone and servers to Gigabit Ethernet can greatly improve network response
times as well as significantly speed up the traffic between your subnetworks.
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’s and tomorrow's rapidly improving switching and routing internetworking technologies.
Switching Technology
Another key development pushing the limits of Ethernet technology is in the field 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 making it possible for a local area network to be divided into
different segments, which are not competing with each other for network transmission capacity, and therefore decreasing
the load on each segment.
The Switch acts as a high-speed selective bridge between the individual segments. Traffic that needs to go from one
segment to another (from one port to another) is automatically forwarded by the Switch, without interfering with any other
segments (ports). This allows the total network capacity to be multiplied, while still maintaining the same network cabling
and adapter cards.
For Fast Ethernet or Gigabit Ethernet networks, a switch is an effective way of eliminating problems of chaining hubs
beyond the "two-repeater limit." A switch can be used to split parts of the network into different collision domains, for
example, making it possible to expand your Fast Ethernet network beyond the 205-meter network diameter limit for
100BASE-TX networks. Switches supporting both traditional 10Mbps Ethernet and 100Mbps Fast Ethernet are also ideal
for bridging between existing 10Mbps networks and new 100Mbps networks.
Switching LAN technology is a marked improvement over the previous generation of network bridges, which were
characterized by higher latencies. Routers have also been used to segment local area networks, but the cost of a router and
the setup and maintenance required make routers relatively impractical. Today's switches are an ideal solution to most
kinds of local area network congestion problems.