3.9.2.1 Network Topology. Flashcards
Define a physical network topology.
Refers to the actual architecture of a network.
Define a logical network topology.
Refers to the flow of data around a network
Outline the two types of physical network topologies:
Star and bus.
Outline a physical star network topology.
Each client, has its own direct connection to the central hub. The hub receives packets for all the clients connected to it and is responsible for delivering them to the correct recipient.
Outline the advantages of a physical star network topology.
Packages sent directly to recipient over a cable connected only to them - meaning other clients cannot see packets that aren’t intended for them.
Easy to add and remove clients.
Each cable has just one device communicating over it, eliminating the possibility of collisions.
The failure of one cable does not affect the rest of the network
Outline the disadvantages of a physical star network topology.
Should the central hub fail, all communication over the network is stopped.
Expensive to install thanks
to the amount of cable required.
Describe a physical bus topology.
A physical bus connects clients to a single cable called a backbone. A device called a
terminator is placed at either end of the backbone.
What does no central hub in a physical bus topology mean?
There is no need for a central hub like in physical star networks and a server can be connected to the backbone just like a client.
Outline the advantages of a physical bus network topology.
There is no central hub, reducing the chances of a network failure and decreasing the cost of installation.
Inexpensive to install as a minimum length of cable is required.
Outline the disadvantages of a physical bus network topology.
Packets are sent through the shared backbone, allowing every client on the
network to see packets that aren’t intended
for them.
The backbone is used for communication by multiple clients, introducing the risk of collisions.
Should the backbone fail, the entire network becomes unusable.
Define a logical bus topology.
A logical bus network delivers packets to all clients on the network whereas a logical star network delivers packets only to their recipient.
Explain how topologies can mix.
If a network is set up as a physical star, it can still behave as a logical bus. Even if the physical connections between clients and the central hub follow that of the physical star
topology, running a bus protocol on the hub allows it to distribute packets to all of the connected clients so as to act like a bus network.
What must a machine have in order to be able to connect to a network?
NIC.
This could allow for a cable or wireless connection.
What else does a NIC dictate?
The speed of data transmission between the device and the network.
What will the NIC have?
A unique MAC address.
