A
1 mbps DSL Modem
B Linksys 7-Port Router w/ Print Server
C D-Link 8-Port Switch
Extended
Star Topology
Star topology where a central hub is connected by vertical cabling
to other hubs that are dependent on it.
Attenuation - Loss of communication signal energy. EIA/TIA-568B
specifies the maximum length of horizontal cabling for unshielded
twisted pair cable is ninety meters. In addition, we learned that
the maximum length for patch cords at the telecommunications outlet/connector
is three meters. We also learned that the maximum length for patch
cords/jumpers at the horizontal cross connect is 6 meters. Thus,
the maximum distance for a run of horizontal cabling that extends
from the hub to any workstation is 100 meters.
In a star topology because each of the horizontal cabling runs can
radiate out from the hub much like the spokes of a wheel, this means
a local area network using this type of topology could cover a 100-meter
by 100-meter area.
When signals first leave a transmitting station, they are clean
and easily recognizable. However, the longer the cable length, the
weaker and more deteriorated the signals become as they pass along
the networking media. If a signal travels beyond that distance,
there is no guarantee that when it reaches a NIC card, the NIC card
will be able to read it.
If a simple star topology cannot provide enough coverage for the
area to be networked, the star topology can be extended by using
internetworking devices that do not result in attenuation of the
signal. When this occurs, the resulting topology is referred to
as an extended star topology.
