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Session Objectives #12. LAN & WAN Differences . Starter: Explain as many differences between a LAN and a WAN as you can. Which network do you think is the most secure and why??. Data Packets.
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LAN & WAN Differences Starter: Explain as many differences between a LAN and a WAN as you can. Which network do you think is the most secure and why??
Data Packets When data is sent from one machine to another over a network, either through the internet or over a LAN, it needs to be collected together in bundles called packets. Packets – bundles of data ready to be transmitted. The size of the ‘message’ doesn’t matter as packages are a standard size, the bigger the message the more packets sent. A data packet consists of several parts or labels Ensuring it is the same as original and not corrupted Where it is going to Where the file Is coming from The data itself Which part of the file it is
Sending data packets When data is bundled into a packet there a 2 ways in which the packet can be sent across a network: circuit switching and packet switching. Circuit Switching – a path between the machines is established first and all packets are sent in order. The path is reserved for the duration of the message and then shuts down Advantages: Packets arrive in the right order. Circuit dedicated to data transfer Disadvantages: Network tied up and could be used more efficiently. It takes a relatively long time to set up the circuit. Packet Switching – Individual packets are sent on to the network and each follows the most convenient route at that time. They will probably arrive in a different order but the number sequence label is read and reordered at the destination machine. Advantages: Does not tie up network and are difficult to intercept messages (more secure) Disadvantages: Under heavy use there can be a delay. Data packets can get lost or become corrupted.
Circuit vs Packet Switching Watch this video clip to help confirm your understanding of the difference between packet and circuit switching. http://www.youtube.com/watch?v=Dq1zpiDN9k4 TASK: In pairs use the iPads to make a fun animation to explain the differences between circuit and packet switching. Highlight how the data is bundled and the advantages and disadvantages of each mehtod.