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DES-3550 Layer 2 Fast Ethernet Switch User’s Guide
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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.
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 decrease 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.
Switch Description
The DES-3550 is equipped with unshielded twisted-pair (UTP) cable ports providing
dedicated 10 or 100 Mbps bandwidth. The Switch has 24 UTP ports and Auto MDI-X/MDI-II
convertible ports that can be used for uplinking to another switch. These ports can be used for
connecting PCs, printers, servers, hubs, routers, switches, and other networking devices. The
dual speed ports use standard twisted-pair cabling and are ideal for segmenting networks into
small, connected subnetworks for superior performance. Each 10/100 port can support up to
200 Mbps of throughput in full-duplex mode.
In addition, the Switch has two Mini-GBIC combo ports. These two, gigabit combo ports are
ideal for connecting to a server or network backbone.