ed in the correct order, even if they arrive out of sequence due to taking different network paths. B1\n- **Error Detection**: It performs error-checking by calculating and verifying a checksum for each packet to detect if any data was corrupted during transit. B1\n- **Reliability and Retransmission**: It manages delivery via acknowledgements; if a packet is lost, delayed, or corrupted, TCP initiates a retransmission request for that specific packet before reassembling the entire file at the destination. B1","marks":4,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"4fb6d979-8e01-45b2-ad82-eee505d19e11","revisionId":"39f6f6f2-3146-41a0-9d2d-a5ac75014aa3","questionNumber":null,"questionType":"LA","specification":"A research facility in Antarctica is transmitting a high-resolution meteorological dataset to a cloud server in London. To facilitate this transmission over the Internet, the data is split into multiple packets which are routed dynamically through an interconnected network of routers, as illustrated in the diagram below.\n\n![Interconnected network of routers directing data packets](https://assets.mathsgenie.co.uk/aqa-qb/d4872e11-0aac-4d02-84ae-d6b2d6f6e873.png)","difficulty":6,"difficultyBand":"medium","totalMarks":5,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"541892de-23cc-44db-86d6-0574f573cc4f","label":null,"content":"Explain the step-by-step process of how these routers direct the packets from the source client to the destination cloud server.","markscheme":"- The router receives a packet from the source device or an upstream router. B1\n- The router extracts and inspects the packet header to identify the destination IP address. B1\n- The router queries its internal routing table (or executes a routing algorithm) to identify the most efficient route or 'next hop' for that IP address. B1\n- The router forwards the packet to the next adjacent router or node along the determined path. B1\n- Because routing is dynamic, if congestion, latency, or link failure occurs on one route (e.g. between $R_1$ and $R_2$), routers adaptively redirect subsequent packets along alternative pathways (such as through $R_3$ or $R_5$). B1","marks":5,"order":0,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_computer_science","summaries":[{"id":"00254646-1893-44fb-a329-75c93c8f7447","difficultyBand":"easy","calculatorUse":null},{"id":"00ba0ade-dfc3-4ee3-9996-d6da7870199d","difficultyBand":"easy","calculatorUse":null},{"id":"026c5d96-0aa7-4c95-bcfd-662538695950","difficultyBand":"easy","calculatorUse":null},{"id":"02751fc9-b48c-4f11-b78e-c1d0d5787974","difficultyBand":"easy","calculatorUse":null},{"id":"03085bff-ef7e-4d1e-97de-d304c985797f","difficultyBand":"easy","calculatorUse":null},{"id":"04e425d9-2dad-4061-94db-b86ac53e27f3","difficultyBand":"medium","calculatorUse":null},{"id":"06c194d5-f71e-4c64-92c7-c1c7c36a0022","difficultyBand":"medium","calculatorUse":null},{"id":"075fb61f-4c42-41a1-86ff-7ea9ca66970d","difficultyBand":"easy","calculatorUse":null},{"id":"0b423ffa-2e76-4113-a772-6d92b992637b","difficultyBand":"medium","calculatorUse":null},{"id":"0c4681c9-b152-4d3c-9c14-800eef8145f6","difficultyBand":"medium","calculatorUse":null},{"id":"10d2a6a9-ef82-4737-bdca-82cea0eec30e","difficultyBand":"easy","calculatorUse":null},{"id":"111cd4fd-ad1e-4b50-ba18-629a3614b53c","difficultyBand":"easy","calculatorUse":null},{"id":"11f6ae43-1c59-478a-8e8b-eef2148553bf","difficultyBand":"easy","calculatorUse":null},{"id":"13145d2c-5778-4b6b-a116-3d3460a43c08","difficultyBand":"medium","calculatorUse":null},{"id":"1418672b-55dd-4a5b-96ab-e235c60ab2ea","difficultyBand":"easy","calculatorUse":null},{"id":"145e41ac-af8b-4529-80f1-2fec8e948521","difficultyBand":"easy","calculatorUse":null},{"id":"1477f48b-8eb3-4b62-9b23-44ce79a5b103","difficultyBa

Networks

Question 13

Networks Questions

Networks

Question 13

Networks Questions