Network Topologies [2.5] Flashcards
What is a device connected to a network referred to as?
A Node.
What is a Star Topology?
A network where each node is connected to a central switch
What are the rules for Star Topologies?
All Nodes indirectly connect to each other through one or more switches. The switch acts as a central point through which all communications are passed.
What are the advantages of Star Topolgioes?
each node is separately connected, therefore a failure of one node or its link, (transmission media), does not affect any other nodes
new nodes can be added to the network simply by connecting them to the switch
star networks tend to have higher performance as a message is passed on to its intended recipient only
What are the disadvantages of Star Topolgies?
the whole network fails if the switch fails as no node can communicate
a wired star topology requires plenty of cable - in a large network this can be expensive
Where are star topologies normally found?
Large organisations, such as educational establishments and businesses where high performance is a must.
What is a Mesh Topolgy?
A network where each node is directly connected to all other nodes.
What are the two types of mesh topology?
Full Mesh Topology
Partial Mesh Toplogy
What are the differences between full mesh topologies and part topologies?
With a full mesh, each node is directly connected to every other node. This enables a message to be sent along many individual routes.
With a partial mesh, not all nodes are connected directly to each other. A partial mesh therefore has fewer routes for a message to travel along than a full mesh but is simpler to implement.
Advantages of Mesh Topology?
messages can be received more quickly if the route to the intended recipient is short
messages should always get through as they have many possible routes on which to travel
multiple connections mean (in theory) that no node should be isolated
multiple connections mean each node can transmit to and receive from more than one node at the same time
new nodes can be added without interruption or interfering with other nodes
Disadvantages of Mesh Topologies?
full mesh networks can be impractical to set up because of the high number of connections needed
many connections require a lot of maintenance
What are wireless networks?
A network that uses wireless WIFI signals to connect nodes.
Wi-Fi signals use radio frequencies in the 2.4 gigahertz (GHz) and 5 GHz wavebands. Each node has a radio transceiver, which allows it to connect to a wireless access point (WAP).
What are the advantages of using WIFI?
new nodes can easily be added without interruption to the network
users can move around freely and still stay connected
What are the disadvantages of using WIFI?
Wi-Fi signals have a limited range, usually no more than 50 metres.
Wi-Fi signals can suffer from electromagnetic interference from other devices and even other Wi-Fi signals. They can also be blocked by walls, leading to dead spots where no signal can be found.
Each WAP only has so much bandwidth to share among connected nodes. The more nodes that are connected, the less bandwidth each receives and the slower communication becomes.
Wi-Fi signals pose a security risk as they can be intercepted by unauthorised users. To overcome this problem, messages need to be encrypted.
Where is WIFI mainly used?
Wi-Fi is seen in a lot of places due to it being easily accessible fast wireless internet
