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Networks - Topologies and protocols (Benefits of networks: (• Good…
Networks - Topologies and protocols
Topology - layout of the nodes withing the network
Node - device connected to a server
Star networks:
Each node has an independent connection to a central switch or server.
Ethernet is the cable which connects a computer to the server.
Prone to failure, when one computer fails the whole system fails.
Mesh networks:
All nodes are involved in the transmission of a message.
There is no single point of failure – no server.
Nodes can talk to each other.
Multiple pathways to follow.
If a computer fails, the system can still run.
More expensive
Bus network:
All nodes are attached to the backbone.
The terminators prevent signal reflection
If there is a problem with the backbone then the network goes down.
Cheap
Prone to collisions
WIFI:
A waveband is divided into channels to allow multiple data streams on one carrier.
Uses two radio frequency bands – 2.4 GHz and 5 GHz
Networks:
• It is a collection of computer systems linked together.
• The network is made from node – devices, links – connections.
• Connections can be caballed or can be wireless.
• Wireless devices use radio waves.
• Most computers are networked via the internet.
Benefits of networks:
• Good communication.
• Shared data.
• Distributed systems – different computers deal with different parts of a task.
• Central control of security, software availability and updates.
• Single point of backup.
• Monitoring user behaviour.
Types of networks:
LAN: Local Area Network
• All on one site.
• Covers small geographic area.
• Infrastructure owned by network owner.
• Either wired with Ethernet cables or wireless with Wi-Fi.
Advantages of LAN's
• Sharing files is easier-network users can access the same files.
• Share the same hardware e.g. a printer.
• Internet connection can be shared between devices connected to the LAN.
• Easier to install and update computers.
• Communicate with LAN users cheaply and easily.
• User accounts can be stored centrally-log in from any device.
WAN: Wide Area Network
• Covers a large geographic area.
• Infrastructure owned by communications companies.
• Connects LANs that are all in different geographical locations.
• Connected using fibre or copper telephone lines, satellite links or radio link.
• An example of a WAN is the internet.
Other Networks:
PAN – Personal Area Network, used for data transmission.
SAN – Storage Area Network, handles large data transfers. Network allows different devices to have back up storage.
VPN – Virtual Private Network, extends a private network over a public network, can’t trace your IP address.
