3
Switching Technology
Another approach to pushing beyond the limits of Ethernet technology
is the development of switching technology. A switch bridge 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 don’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.
For Fast 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, 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 the
existing 10Mbps networks and the 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, the setup and maintenance required
make routers relatively impractical. Today switches are an ideal
