TCP Lab:\tScenario\/Summary:\tIn this lab, we’ll investigate the behavior of TCP in detail. We’ll do so by analyzing a\ttrace of the TCP segments sent and received in transferring a 150KB file (containing the\ttext of Lewis Carrol’s\u00a0Alice’s Adventures in Wonderland) from your computer to a\tremote server. We’ll study TCP’s use of sequence and acknowledgement numbers for\tproviding reliable data transfer; we’ll see TCP’s congestion control algorithm “\ufffd slow start\tand congestion avoidance “\ufffd in action; and we’ll look at TCP’s receiver-advertised flow\tcontrol mechanism. We’ll also briefly consider TCP connection setup and we’ll\tinvestigate the performance (throughput and round-trip time) of the TCP connection between your computer and the server.\tBefore beginning this lab, you’ll probably want to review Sections 3.5 and 3.7 in the text.\tDeliverables:\tLab Report with overview, activities, and summary\tAnswers to questions included in lab\tCaptured screenshots of data\tiLab Steps\tStep 1:\u00a0Capturing a bulk TCP transfer from your computer to a remote server\tBefore beginning our exploration of TCP, we’ll need to use Wireshark to obtain a packet\ttrace of the TCP transfer of a file from your computer to a remote server. You’ll do so by\taccessing a Web page that will allow you to enter the name of a file stored on your\tcomputer (which contains the ASCII text of\u00a0Alice in Wonderland), and then transferring the\tfile to a Web server using the HTTP POST method (see Section 2.2.3 in the text). We’re\tusing the POST method rather than the GET method, as we’d like to transfer a large\tamount of data\u00a0from\u00a0your computer to another computer. Of course, we’ll be running\tWireshark during this time to obtain the trace of the TCP segments sent and received from your computer.\tDo the following:\t\u00b7\u00a0 Start up your Web browser. Go the http:\/\/gaia.cs.umass.edu\/wiresharklabs\/\talice.txt and retrieve an ASCII copy of\u00a0Alice in Wonderland.\u00a0Store this file\ton your computer.\t\u00b7\u00a0 Next, go to http:\/\/gaia.cs.umass.edu\/wireshark-labs\/TCP-wireshark-file1.html.\tIf you are unable to run Wireshark on a live network connection, you can download a\tpacket trace file that was captured while following the steps above on one of the author’s\tcomputers. (Download the zip file in your Doc Sharing folder http:\/\/gaia.cs.umass.edu\/wireshark-labs\/wireshark-traces.zip and extract the file tcpethereal-trace-1. The traces in this zip file were collected by Wireshark running on one of the author’s computers, while performing the steps indicated in the Wireshark lab. Once you have downloaded the trace, you can load it into Wireshark and view the trace using the\u00a0File\u00a0pull-down menu, choosing\u00a0Open, and then selecting the tcp-ethereal-trace-1 trace file). You may well find it valuable to download this trace even if you’ve captured your own trace and use it, as well as your own trace, when you explore the questions below.\tStep 2:\u00a0A first look at the captured trace\tAnswer the following questions by opening the Wireshark captured-packet file\u00a0tcpethereal-\ttrace-1\u00a0in http:\/\/gaia.cs.umass.edu\/wireshark-labs\/wireshark-traces.zip (that is,\tdownload the trace and open that trace in Wireshark; see Footnote 2). Whenever possible,\twhen answering a question, you should hand in a printout of the packet(s) within the trace\tthat you used to answer the question asked. Annotate the printout to explain your\tanswer. To print a packet, use\u00a0File->Print, choose\u00a0Selected Packet Only, choose\u00a0Packet\tSummary Line,\u00a0and select the minimum amount of packet detail that you need to answer\tthe question.<\/p>\n","protected":false},"excerpt":{"rendered":"
TCP Lab: Scenario\/Summary: In this lab, we’ll investigate the behavior of TCP in detail. We’ll do so by analyzing a trace of the TCP segments sent and received in transferring a 150KB file (containing the text of Lewis Carrol’s\u00a0Alice’s Adventures Read More …<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-210446","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts\/210446","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/comments?post=210446"}],"version-history":[{"count":0,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/posts\/210446\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/media?parent=210446"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/categories?post=210446"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.benedictsol.com\/blogs\/wp-json\/wp\/v2\/tags?post=210446"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}