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5 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Topology |
Topology is the term used to describe how devices are connected and how messages flow from device to device. There are two types of network topologies:
· The physical topology describes the physical way the network is wired. · The logical topology describes the way in which messages are sent. |
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Bus |
A physical bus topology consists of a trunk cable with nodes either inserted directly into the trunk, or nodes tapping into the trunk using offshoot cables called drop
cables. · Signals travel from one node to all other nodes on the bus. · A device called a terminator is placed at both ends of the trunk cable. · Terminators absorb signals and prevent them from reflecting repeatedly back and forth on the cable. The physical bus: · Requires less cable than the star · Can be difficult to isolate cabling problems A broken cable anywhere on the bus breaks the termination and preventscommunications between any device on the network. |
Messages are sent to all devices connected tothe bus. |
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Ring |
A ring topology connects neighboring nodes until they form a ring. Signals travel in one direction around the ring. In ring topologies, each device on the network acts as a repeater to send the signal to the next device. With a ring: * Installation Requires careful planning to create a continuous ring. * Isolating problems can require going to several physical locations along the ring. * A malfunctioning node or cable break can prevent signals from reaching nodes further along on the ring. |
Messages are sent from device-to-device in a predetermined order until they reach the destination device. |
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Star |
A star topology uses a hub or switch to concentrate all network connections to a single physical location. Today it is the most popular type of topology for a LAN.With the star:
* All network connections are located in a single place, which makes it easy to troubleshoot and reconfigure. * Nodes can be added to or removed from the network easily. * Cabling problems usually affect only one node. * Requires more cable than any other topology. Every node has its own cable. a
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Messages are sent directly to (and only to) the destination device. |
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Mesh |
A mesh topology exists when there are multiple paths between any two nodes on a network. Mesh Topologies are created using point-to-point connections. This increases the network's fault tolerance because alternate paths can be used when one path fails. Two variations of mesh topologies exist:
· Partial Mesh--Some Redundant paths exist. · Full Mesh--Every Node has a point-to-point connection with every other node.
Full mesh topologies are usually impractical because the number of connections increases dramatically with every new node added to the network. However, a full mesh topology becomes more practical through the implementation of an ad-hoc wireless network. With this topology,every wireless network card can communicate directly with any other wireless network card on the network. A separate and dedicated network interface and cable for each host on the network is not required.
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