2
Switching Technology
Another approach to pushing 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. It transmits packets among connected
Ethernet or Fast Ethernet LAN segments.
Switching is a cost-effective way of increasing the total
network bandwidth available to users on a local area
network. A switch divides a local area network into
multiple, separate
segments
. Each segment has it’s own full
Ethernet or Fast Ethernet bandwidth that doesn’t compete
with the other segments for network transmission.
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 and blocks traffic
that does not need to be transmitted. By doing this the total
network bandwidth is multiplied, while still maintaining the
same network cabling and adapter cards.
For Fast Ethernet networks, a switch is an effective way of
eliminating the problem 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 a Fast Ethernet network beyond the 205-meter
network diameter limit. Switches supporting both
traditional 10Mbps Ethernet and 100Mbps Fast Ethernet
are ideal for bridging between existing 10Mbps networks and
new 100Mbps networks.
