|
Topologies
A network topology is the geometric arrangement of nodes and
cable links in a LAN, and is used in two general
configurations: bus and star. These two topologies define
how nodes are connected to one another. A node is an active
device connected to the network, such as a computer or a
printer. A node can also be a piece of networking equipment
such as a hub, switch or a router.
A bus topology consists of nodes linked together in a series
with each node connected to a long cable or bus. Many nodes
can tap into the bus and begin communication with all other
nodes on that cable segment. A break anywhere in the cable
will usually cause the entire segment to be inoperable until
the break is repaired. Examples of bus topology include
10BASE2 and 10BASE5.
10BASE-T Ethernet and Fast Ethernet use a star topology, in
which access is controlled by a central computer. Generally
a computer is located at one end of the segment, and the
other end is terminated in central location with a hub.
Because UTP is often run in conjunction with telephone
cabling, this central location can be a telephone closet or
other area where it is convenient to connect the UTP segment
to a backbone.
The primary advantage of this type of network is
reliability, for if one of these 'point-to-point' segments
has a break, it will only affect the two nodes on that link.
Other computer users on the network continue to operate as
if that segment were nonexistent.
|