1. GCSE Computing#BristolMet Session Objectives#16 MUST describe the hardware needed to connect to the Internet and describe the nature of the Internet. SHOULD explain the different roles computers play in a client server network and a peer to peer network. COULD explain the terms IP addressing, MAC addressing, packets and protocols, and explain the need for IP addressing to manage internet resources. Create a network of Raspberry Pis and ping to test network connections.

2. GCSE Computing#BristolMet Key Words

3. GCSE Computing#BristolMet 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 Source Address Destination Address Packet Sequence Number DATA Error Checking (Checksum) Where the file Is coming from Where it is going to Which part of the file it is The data itself Ensuring it is the same as original and not corrupted

4. GCSE 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, the bit rate, transmission modes and error checking.

5. GCSE 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

6. GCSE 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

7. GCSE Computing#BristolMet Practical Investigation TASK: Follow the ‘making a network connection’ 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?