LEARNING OBJECTIVES
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Be able to differentiate between network topologies and their uses.
SUCCESS CRITERIA
Success Criteria:
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Build network topologies.
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Create a presentation about topologies not covered in the lesson.
1.5 Network topologies, protocols and layers
Learners should have studied the following:
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LO1 star and mesh network topologies
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WiFi:
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frequency and channels
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encryption
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ethernet
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the uses of IP addressing, MAC addressing, and protocols including:
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TCP/IP (Transmission Control Protocol/Internet Protocol
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HTTP (Hyper Text Transfer Protocol)
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HTTPS (Hyper Text Transfer Protocol Secure)
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FTP ( File Transfer Protocol
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POP ( Post Office Protocol)
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IMAP (Internet Message Access Protocol)
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SMTP (Simple Mail Transfer Protocol)
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the concept of layers
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packet switching
KEYWORDS
Network topology- the physical structure of a network
Data collision - the result of two devices on the same network attempting to transmit data at the same time down the same connection.
HOME LEARNING
There are other topologies that weren't covered in today's lesson. Research what these topologies are and create a PowerPoint/PowToons presentation highlighting their advantages and disadvantages and when and where are they used. There should be a minimum of 3 topologies.
Networks - LESSON 5
Network topologies and protocols
STARTER
Question and answer session about how much you can remember so far.
Ask your peer a question if they get it right they get the chance to ask a question
Click on the link to access the worksheet for this task.
A network topology is essentially the structure of a network and they all work in the same way. It is the way in which all the computers and devices are connected together in a network. The computers on the network prepares a signal to send to another device, which is located by an address of some sort. The signal is then placed on a transmission medium which we looked at in the last lesson.
Networks can be laid out in different ways. This layout is called its topology and this will affect the cost and performance of the network.
We need to know the structure of two main network topologies; these are star topology and mesh topology.
lo1- Topologies
lo1-Star network topology
The star topology is the most common network layout. In this topology there is a server that all computers are connected to using hubs or switches. Star networks tend to be fast and reliable because each node has its own connection to the server. If a computer fails in the star topology it has little effect on the other computers, unless it is the server in which case it is catastrophic.
The security of a star topology is generally quite high
as the traffic from each computer goes through the
central server or computer before interacting with another
computer.
Data collisions are less frequent on this topology as
each computer has its own dedicated cable that
connects it to the server.
This also speeds up overall throughput.
The setting up of this network structure can be
expensive to set up as it needs a central controlling
computer and a large amount of cabling to connect each
computer.
lo1-Mesh Network topology
All nodes are involved in the transmission of a message. There are multiple paths between the nodes and no central router is required, the nodes can talk directly to each other.
A mesh topology can either be a full mesh or a partial. In a full mesh topology each computer in the network is directly connected to every other computer in the network. In a partial mesh topology, computers that need to interact the most with each other, for example exchange data, are the ones that are connected together.
It is easy to add further computers into a mesh network, but this can often take quite a lot a cabling. The network structure itself needs a great deal of cabling to be set up; this can be an expensive cost.
If one connection to a computer fails in this type of network, it has little effect on the network as the computer can find another working connection in a mesh network; this is often why a partial mesh will be set up instead of a full mesh.
A full mesh network topology layout
A partial mesh network topology layout
lo1 Other topologies
Bus topology is used very little nowadays. They have a backbone to which the nodes are attached. Bus networks are prone to data collisions and can be unreliable because a fault in the backbone will disrupt the entire network.
Ring topology as the name implies, are based on nodes arranged in a circle. Each node is connected to exactly two other nodes. Messages pass through each computer, which is then responsible for passing the message on.
Data is sent is packets and if a computer has a
message to send, it modifies packets as they pass through it.
When a message is received, the receiving computer
sends a message back to the originator to acknowledge
delivery. As with bus networks,
a fault in the ring connection will disrupt the entire network.
