Question 1 (30%) Consider the headers of HTTP request and response messages below: HTTP Request: GET...

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Question 1 (30%) Consider the headers of HTTP request and response messages below: HTTP Request: GET /f/miscellaneous/9/SPEED-logo11.svg HTTP/1.1 Accept: image/avif, image/webp, image/apng, image/svg+xml, image/*,*/*;q=0.8 Accept-Encoding: gzip, deflate, br Accept-Language: en-US,en;q=0.9, zh-CN;q=0.8, zh;q=0.7, zh-TW;q=0.6 Cache-Control: no-cache Connection: keep-alive Host: www.speed-polyu.edu.hk Pragma: no-cache Referer: https://www.speed-polyu.edu.hk/programme/applied-sciences-iswt Sec-Fetch-Dest: image Sec-Fetch-Mode: no-cors Sec-Fetch-Site: same-origin User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/105.0.0.0 Safari/537.36 sec-ch-ua: "Google Chrome"; v="105", "Not) A; Brand";v="8", "Chromium"; v="105" sec-ch-ua-mobile: ?0 sec-ch-ua-platform: "Windows" HTTP Response: HTTP/1.1 200 OK Date: Wed, 14 Sep 2022 11:14:48 GMT Server: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips Strict-Transport-Security: max-age=63072000; includeSubdomains; preload X-Content-Type-Options: nosniff X-Frame-Options: SAMEORIGIN Content-Security-Policy: upgrade-insecure-requests; X-Xss-Protection: 1; mode=block Referrer-Policy: no-referrer-when-downgrade Last-Modified: Mon, 13 Jan 2020 08:42:46 GMT ETag: "89e9-59c0175aled80" Accept-Ranges: bytes Content-Length: 35305 Keep-Alive: timeout=5, max=97 Connection: Keep-Alive Content-Type: image/svg+xml Question 2 (30%) Two common types of access network are DSL network and cable network. While DSL network provides dedicated line connecting each home to the central office, such connection is shared among multiple homes in cable network. (a) In both DSL network and cable network, the downstream transmission rate is much higher than the upstream transmission rate. Explain why it is the case. (10 marks) (b) Compare the advantages and disadvantages between dedicated line in DSL network and shared cable in cable network. (10 marks) (c) In the Internet, access networks are usually maintained by ISP. There are also other entities called IXP. What is IXP? What is the relationship between ISP and IXP? (10 marks) Question 1 (30%) Consider the headers of HTTP request and response messages below: HTTP Request: GET /f/miscellaneous/9/SPEED-logo11.svg HTTP/1.1 Accept: image/avif, image/webp, image/apng, image/svg+xml, image/*,*/*;q=0.8 Accept-Encoding: gzip, deflate, br Accept-Language: en-US,en;q=0.9, zh-CN;q=0.8, zh;q=0.7, zh-TW;q=0.6 Cache-Control: no-cache Connection: keep-alive Host: www.speed-polyu.edu.hk Pragma: no-cache Referer: https://www.speed-polyu.edu.hk/programme/applied-sciences-iswt Sec-Fetch-Dest: image Sec-Fetch-Mode: no-cors Sec-Fetch-Site: same-origin User-Agent: Mozilla/5.0 AppleWebKit/537.36 Chrome/105.0.0.0 Safari/537.36 sec-ch-ua: "Google Chrome"; v="105", "Not) A; Brand";v="8", "Chromium"; v="105" sec-ch-ua-mobile: ?0 sec-ch-ua-platform: "Windows" HTTP Response: HTTP/1.1 200 OK Date: Wed, 14 Sep 2022 11:14:48 GMT Server: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips Strict-Transport-Security: max-age=63072000; includeSubdomains; preload X-Content-Type-Options: nosniff X-Frame-Options: SAMEORIGIN Content-Security-Policy: upgrade-insecure-requests; X-Xss-Protection: 1; mode=block Referrer-Policy: no-referrer-when-downgrade Last-Modified: Mon, 13 Jan 2020 08:42:46 GMT ETag: "89e9-59c0175aled80" Accept-Ranges: bytes Content-Length: 35305 Keep-Alive: timeout=5, max=97 Connection: Keep-Alive Content-Type: image/svg+xml Question 2 (30%) Two common types of access network are DSL network and cable network. While DSL network provides dedicated line connecting each home to the central office, such connection is shared among multiple homes in cable network. (a) In both DSL network and cable network, the downstream transmission rate is much higher than the upstream transmission rate. Explain why it is the case. (10 marks) (b) Compare the advantages and disadvantages between dedicated line in DSL network and shared cable in cable network. (10 marks) (c) In the Internet, access networks are usually maintained by ISP. There are also other entities called IXP. What is IXP? What is the relationship between ISP and IXP? (10 marks)