作业tcp实验报告gaia.cs umass edu的TCP端口为

WhatistheIPaddressandTCPportnumberusedbythecomputer(source)thatistransferringthefileto?Toanswerthisquestion,it’sprobablyeasiesttoselectanHTTPmessageandexplorethedetailsoftheTCPpacketusedtocarrythisHTTPmessage,usingthe“detailsoftheselectedpacketheaderwindow”(refertoFigure2inthe“GettingStartedwithWireshark”Labifyou’reuncertainabouttheWiresharkwindows.客户端的IP客户端的TCP端口为WhatistheIP?OnwhatportnumberisitsendingandreceivingTCPsegmentsforthisconnection?IP2TCP80WhatistheIPaddressandTCPportnumberusedbyyourcomputer(source)totransferthefileto?我的客户端的IP我的客户端的TCP端口为WhatisthesequencenumberoftheTCPSYNsegmentthatisusedtoinitiatetheTCPconnectionbetweenthecomputerand?WhatisitinthesegmentthatidentifiesthesegmentasaSYNsegment?theseqofSYNusedtoinitiateisflagslastsecondbitidentifiesthatitisaSYNWhatisthesequencenumberoftheSYNACKsegmentsentbytothecomputerinreplytotheSYN?WhatisthevalueoftheACKnowledgementfieldintheSYNACKsegment?Howdiddeterminethatvalue?WhatisitinthesegmentthatidentifiesthesegmentasaSYNACKsegment?sequenceno.ofSYNACKisthevalueofACKnowledgementisflagslastfifthandlastsecondbitsidentifyitisaSYNACKWhatisthesequencenumberoftheTCPsegmentcontainingtheHTTPPOSTcommand?NotethatinordertofindthePOSTcommand,you’llneedtodigintothepacketcontentfieldatthebottomoftheWiresharkwindow,lookingforasegmentwitha“POST”withinitsDATAfield.seqno.isConsidertheTCPsegmentcontainingtheHTTPPOSTasthefirstsegmentintheTCPconnection.WhatarethesequencenumbersofthefirstsixsegmentsintheTCPconnection(includingthesegmentcontainingtheHTTPPOST)?Atwhattimewaseachsegmentsent?WhenwastheACKforeachsegmentreceived?GiventhedifferencewheneachTCPsegmentwassent,andwhenitsacknowledgementwasreceived,whatistheRTTvalueforeachofthesixsegments?WhatistheEstimatedRTTvalue(seepage249intext)afterthereceiptofeachACK?AssumethatthevalueoftheEstimatedRTTisequaltothemeasuredRTTforthefirstsegment,andtheniscomputedusingtheEstimatedRTTequationonpage249forallsubsequentsegments.Note:WiresharkhasanicefeaturethatallowsyoutoplottheRTTforeachoftheTCPsegmentssent.SelectaTCPsegmentinthe“listingofcapturedpackets”windowthatisbeingsentfromthetotheserver.Thenselect:Statistics->TCPStreamGraph->RoundTripTimeGraph.seq分别是 发送时 0.026477（连接建立后收到窗口大小是5840，一开始发送 0.041737（发完第一个以后，接收窗口剩余够1514，发送（接收到第一个的确认 0.054026（被通知窗口6780后发送 0.054690（上一个发送了1514长度，剩余够1514，发送（接收到第二个的确认 0.077405（被通知窗口8760后发送 0.078157（发送完上一个以后，剩余窗口仍够1514，发送RTT0.053937-0.077294-0.124885-0.169118-0.217299-0.267802-0.078157=0.1ERTT=7/8*ERTT+ERTT WhatisthelengthofeachofthefirstsixTCPWhatistheminimumamountofavailablebufferspaceadvertisedatthereceivedfortheentiretrace?Doesthelackofreceiverbufferspaceeverthrottlethesender? ……发送方突然减少了发送的长Arethereanyretransmittedsegmentsinthetracefile?Whatdidyoucheckfor(inthetrace)inordertoanswerthisquestion?HowmuchdatadoesthereceivertypicallyacknowledgeinanACK?CanyouidentifycaseswherethereceiverisACKingeveryotherreceivedsegment(seeTable3.2onpage257inthetext).Whatisthethroughput(bytestransferredperunittime)fortheTCPconnection?Exinhowyoucalculatedthisvalue.5.455830-0.0264775.4294秒164090/5.4294=30.222KB/sUsetheTime-Sequence-Graph(Stevens)plottingtooltoviewsequencenumberversustimeplotofsegmentsbeingsentfromthetotheserver.CanyouidentifywhereTCP’sslowstartphasebeginsandends,andwherecongestionavoidancetakesover?CommentonwaysinwhichthemeasureddatadiffersfromtheidealizedbehaviorofTCPthatwe’vestu