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A-Level Computing#BristolMet Session Objectives#13 MUST define the term network protocol SHOULD describe what network protocols do COULD explain why protocols are needed for computers to communicate Create a network of raspberry pis and ping to test connection.

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A-Level Computing#BristolMet Protocols The word protocol means a set of rules. Therefore Network Protocol a set of rules or standards that control the transmission of data between devices. These rules will include that method of transmission (serial or parallel, the bit rate, transmission modes (simplex, duplex, half) and error checking. If using parity both computers would need to be using even parity or odd. If there are any differences to any of these rules then messages would be never be accepted.

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A-Level Computing#BristolMet Protocol Layers Protocols are organised into layers which link into each other. This means it is possible to tweak individual layers without affecting the whole network standard. Protocols can be divide into 2 parts: logically based and physically based. What might these 2 parts consist of? As you will see the logical rules that can be applied depend on the physical rules (or infrastructure) that is already in place. PhysicalLogical PhysicalLogical Wired or Wireless?Concerns the data itself? If wired, what cable to use??Serial or parallel transmission? Fibre optic, cat 5 e, coaxial etcWhat mode to be used? Simplex etc If wireless, what frequency, channel etc? Bit rate to send the data at and how much to send at a time. Error checking method, parity, echo e

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A-Level Computing#BristolMet Examples of Protocols There are many protocols that have been developed over the years. TASK: Create a table and research the meaning and application Of the following protocols. ProtocolMeaningApplication DNS HTTP TCP/IP TLS/SSL ProtocolMeaningApplication DNSDomain Name System Translates domain names such as bristolmet.net into IP addresses HTTPHypertext Transfer Protocol For copying files from one host to another. TCP/IPTransmission Control Protocol/Internet Protocol Set of rules that organise data transmission over the internet. TLS/SSLTransport Layer Security/Secure Sockets Layer Cryptographic protocols designed for secure communications

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A-Level Computing#BristolMet Practical Investigation TASK: Follow the making a network connectiom tutorials and attempt to create a direct network connection to the internet using a laptop (with wifi) and a raspberry pi. Answer the following questions: 1.What is the IP address of your raspberry pi 2.Explain what an IP address is? 3.Discuss why you cannot connect a raspberry directly to a network?