計算機及通信網(wǎng)絡(luò)實驗報告

..>計算機與通信網(wǎng)絡(luò)實驗報告041220111戴妍實驗一隱終端和暴露終端問題分析一、實驗設(shè)定：根本參數(shù)配置：仿真時長100s；隨機數(shù)種子1；仿真區(qū)域2000*2000；節(jié)點數(shù)4。節(jié)點位置配置：本實驗用[1]、[2]、[3]、[4]共兩對節(jié)點驗證隱終端問題。節(jié)點[1]、[2]距離為200m，節(jié)點[3]、[4]距離為200m，節(jié)點[2]、[3]距離為370m。業(yè)務(wù)流配置：業(yè)務(wù)類型為恒定比特流CBR。[1]給[2]發(fā)，發(fā)包間隔為，發(fā)包大小為512bytes；[3]給[4]發(fā)，發(fā)包間隔為，發(fā)包大小為512bytes。二、實驗結(jié)果：Node:1,Layer:AppCbrClient,(0)Serveraddress:20Node:1,Layer:AppCbrClient,(0)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(0)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(0)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(0)Throughput(bitspersecond):409600Node:2,Layer:AppCbrServer,(0)Clientaddress:1Node:2,Layer:AppCbrServer,(0)LastpacketreceivedNode:2,Layer:AppCbrServer,(0)Sessionstatus:NotclosedNode:2,Layer:AppCbrServer,(0)Totalnumberofbytesreceived:4975616Node:2,Layer:AppCbrServer,(0)Totalnumberofpacketsreceived:9718Node:2,Layer:AppCbrServer,(0)Throughput(bitspersecond):398078Node:3,Layer:AppCbrClient,(0)Serveraddress:4Node:3,Layer:AppCbrClienNode:3,Layer:AppCbrClient,(0)Sessionstatus:NotclosedNode:3,Layer:AppCbrClient,(0)Totalnumberofbytessent:5120000Node:3,Layer:AppCbrClient,(0)Totalnumberofpacketssent:10000Node:3,Layer:AppCbrClient,(0)Throughput(bitspersecond):409600Node:4,Layer:AppCbrServer,(0)Clientaddress:3Node:4,Layer:Node:4,Layer:AppCbrServer,(0)Sessionstatus:NotclosedNode:4,Layer:AppCbrServer,(0)Totalnumberofbytesreceived:5120000Node:4,Layer:AppCbrServer,(0)Totalnumberofpacketsreceived:10000Node:4,Layer:AppCbrServer,(0)Throughput(bitspersecond):409612通過仿真結(jié)果可以看出，節(jié)點[2]無法收到數(shù)據(jù)。由于節(jié)點[3]是節(jié)點[1]的一個隱終端，節(jié)點[1]無法通過物理載波檢測偵聽到節(jié)點[3]的發(fā)送，且節(jié)點[3]在節(jié)點[2]的傳輸范圍外，節(jié)點[3]無法通過虛擬載波檢測延遲發(fā)送，所以在節(jié)點[1]傳輸數(shù)據(jù)的過程中，節(jié)點[3]完成退避發(fā)送時將引起沖突。三、課后思考1、RTS/CTS能完全解決隱終端問題嗎？如果不能，請說明理由。答：能。對于隱發(fā)送終端問題，[2]和[3]使用控制報文進(jìn)展握手〔RTS-CTS〕，聽到回應(yīng)握手信號的[3]知道自己是隱終端，便能延遲發(fā)送；對于隱承受終端問題，在多信道的情況下，[3]給[4]回送CTS告訴[4]它是隱終端，現(xiàn)在不能發(fā)送報文，以防止[4]收不到[3]的應(yīng)答而超時重發(fā)浪費帶寬。2、如何設(shè)計仿真場景來驗證暴露終端問題？答：只需更改業(yè)務(wù)流配置：業(yè)務(wù)類型為恒定比特流CBR。[2]給[1]發(fā)，發(fā)包間隔為，發(fā)包大小為512bytes；[3]給[4]發(fā)，發(fā)包間隔為，發(fā)包大小為512bytes。觀察在[2]給[1]發(fā)送數(shù)據(jù)的同時，[3]給[4]發(fā)送數(shù)據(jù)會不會被影響。3、如何設(shè)計協(xié)議使暴露終端場景下的流實現(xiàn)并發(fā)？答：至少要使用兩個信道資源，在數(shù)據(jù)信道上進(jìn)展RTS-CTS握手，在數(shù)據(jù)信道上發(fā)送數(shù)據(jù)報文。在[2]給[1]發(fā)送數(shù)據(jù)報文時，[3]也想向[4]發(fā)送數(shù)據(jù)報文，通過控制信道向[4]發(fā)送RTS，[4]也從控制信道向[3]回送CTS，這樣[3]就不會因為[2]的數(shù)據(jù)信號和[4]的回應(yīng)信號產(chǎn)生碰撞而聽不到[4]的回應(yīng)了。這樣就可以實現(xiàn)并發(fā)了。實驗二無線局域網(wǎng)DCF協(xié)議飽和吞吐量驗證實驗設(shè)定根本參數(shù)配置：仿真時長100S隨機數(shù)種子1仿真區(qū)域150*150節(jié)點數(shù)100。業(yè)務(wù)流配置：業(yè)務(wù)類型為CBR，發(fā)包大小為512bytes，發(fā)包間隔為，分別測出5、10、15、20、25、30、35、40、45、50條流的吞吐量。二、實驗結(jié)果：5條：Node:1,Layer:AppCbrClient,(4)Serveraddress:55Node:1,Layer:AppCbrClient,(4)Firstpacketsentat[s]:Node:1,Layer:AppCbrClient,(4)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(4)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(4)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(4)Throughput(bitspersecond):409600Node:1,Layer:AppCbrClient,(3)Serveraddress:54Node:1,Layer:AppCbrClient,(3)FirstpackNode:1,Layer:AppCbrClient,(3)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(3)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(3)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(3)Throughput(bitspersecond):409600Node:1,Layer:AppCbrClient,(2)Serveraddress:53Node:1,Layer:AppCbrClient,(Node:1,Layer:AppCbrClient,(2)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(2)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(2)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(2)Throughput(bitspersecond):409600Node:1,Layer:AppCbrClient,(1)Serveraddress:52Node:1,Layer:Node:1,Layer:AppCbrClient,(1)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(1)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(1)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(1)Throughput(bitspersecond):409600Node:1,Layer:AppCbrClient,(0)Serveraddress:51Node:Node:1,Layer:AppCbrClient,(0)Sessionstatus:NotclosedNode:1,Layer:AppCbrClient,(0)Totalnumberofbytessent:5120000Node:1,Layer:AppCbrClient,(0)Totalnumberofpacketssent:10000Node:1,Layer:AppCbrClient,(0)Throughput(bitspersecond):409600Node:51,Layer:AppCbrServer,(0)Clientaddress:1Node:51,Layer:AppCbrServer,(0)Sessionstatus:NotclosedNode:51,Layer:AppCbrServer,(0)Totalnumberofbytesreceived:5102592Node:51,Layer:AppCbrServer,(0)Totalnumberofpacketsreceived:9966Node:51,Layer:AppCbrServer,(0)Throughput(bitspersecond):408219Node:52,Layer:AppCbrServer,(1)Clientaddress:1Node:52,Layer:AppCbrServer,(1)LastpacketreceivNode:52,Layer:AppCbrServer,(1)Sessionstatus:NotclosedNode:52,Layer:AppCbrServer,(1)Totalnumberofbytesreceived:5102592Node:52,Layer:AppCbrServer,(1)Totalnumberofpacketsreceived:9966Node:52,Layer:AppCbrServer,(1)Throughput(bitspersecond):408233Node:53,Layer:AppCbrServer,(2)Clientaddress:1Node:53,Layer:AppCbrSerNode:53,Layer:AppCbrServer,(2)Sessionstatus:NotclosedNode:53,Layer:AppCbrServer,(2)Totalnumberofbytesreceived:3926016Node:53,Layer:AppCbrServer,(2)Totalnumberofpacketsreceived:7668Node:53,Layer:AppCbrServer,(2)Throughput(bitspersecond):314112Node:54,Layer:AppCbrServer,(3)Clientaddress:1Node:Node:54,Layer:AppCbrServer,(3)Sessionstatus:NotclosedNode:54,Layer:AppCbrServer,(3)Totalnumberofbytesreceived:22016Node:54,Layer:AppCbrServer,(3)Totalnumberofpacketsreceived:43Node:54,Layer:AppCbrServer,(3)Throughput(bitspersecond):1761Node:55,Layer:AppCbrServer,(4)Clientaddress:1Node:55,Layer:AppCbrServer,(4)FirstpacketreceivedNode:55,Layer:AppCbrServer,(4)Sessionstatus:NotclosedNode:55,Layer:AppCbrServer,(4)Totalnumberofbytesreceived:22016Node:55,Layer:AppCbrServer,(4)Totalnumberofpacketsreceived:43Node:55,Layer:AppCbrServer,(4)Throughput(bitspersecond):176110、15、20、25、30、35、40、45、50條省略各發(fā)送節(jié)點發(fā)包間隔較大，當(dāng)網(wǎng)絡(luò)中發(fā)送節(jié)點較少時，網(wǎng)絡(luò)還未飽和。逐漸往網(wǎng)絡(luò)中增加負(fù)載，網(wǎng)絡(luò)總吞吐量逐漸增大，之后，網(wǎng)絡(luò)吞吐量逐漸趨向于平穩(wěn)，此時，網(wǎng)絡(luò)即到達(dá)了飽和狀態(tài)。三、課后思考1、總結(jié)協(xié)議飽和吞吐量和哪些因素有關(guān)。任選一個時隙，網(wǎng)絡(luò)中有節(jié)點在發(fā)送數(shù)據(jù)的概率當(dāng)有節(jié)點在發(fā)送數(shù)據(jù)包時，數(shù)據(jù)包發(fā)送成功的概率數(shù)據(jù)包發(fā)送成功和發(fā)送失敗所需的時間2、為什么在數(shù)據(jù)包長度較長時，采用RTS/CTS模式更合理？"隱藏終端"多發(fā)生在大型單元中〔一般在室外環(huán)境〕，這將帶來效率損失，并且需要錯誤恢復(fù)機制。當(dāng)需要傳送大容量文件時，尤其需要杜絕"隱藏終端"現(xiàn)象的發(fā)生。3、本實驗中提出的馬爾科夫鏈模型只適用于單跳模型，假設(shè)應(yīng)用到多跳網(wǎng)絡(luò)中時，需如何改進(jìn)？于定長時隙的多跳adhoc網(wǎng)絡(luò)DCF協(xié)議馬爾可夫鏈模型實驗三動態(tài)源路由協(xié)議路由選擇驗證一、實驗設(shè)定根本參數(shù)配置：仿真時長100S；隨機數(shù)種子1；仿真區(qū)域2000*2000；節(jié)點數(shù)5。節(jié)點位置配置：用節(jié)點[1]-[5]來驗證DSR路由協(xié)議的路由發(fā)現(xiàn)過程。[1]和[2]、[2]和[3]、[3]和[4]、[3]和[5]、[4]和[6]、[5]和[6]之間距離為200m。設(shè)置業(yè)務(wù)流：[1]給[2]發(fā)，發(fā)包間隔，發(fā)包大小512Bytes。設(shè)置節(jié)點移動性：節(jié)點[1]為移動節(jié)點，仿真過程中繞網(wǎng)格拓?fù)滢D(zhuǎn)一圈。二、實驗結(jié)果：Time(s):1.000001000,Node:1,Routepath:2Time(s):2.000001000,Node:1,Routepath:2Time(s):3.000001000,Node:1,Routepath:2Time(s):4.000001000,Node:1,Routepath:2Time(s):5.000001000,Node:1,Routepath:2Time(s):6.000001000,Node:1,Routepath:2Time(s):7.000001000,Node:1,Routepath:2Time(s):8.000001000,Node:1,Routepath:4-2Time(s):9.000001000,Node:1,Routepath:4-2Time(s):10.000001000,Node:1,Routepath:4-2Time(s):11.000001000,Node:1,Routepath:4-2Time(s):12.000001000,Node:1,Routepath:4-2Time(s):13.000001000,Node:1,Routepath:4-2Time(s):14.000001000,Node:1,Routepath:4-2Time(s):15.000001000,Node:1,Routepath:4-2Time(s):16.000001000,Node:1,Routepath:4-2Time(s):17.000001000,Node:1,Routepath:4-2Time(s):18.000001000,Node:1,Routepath:4-2Time(s):19.000001000,Node:1,Routepath:4-2Time(s):20.000001000,Node:1,Routepath:4-2Time(s):21.000001000,Node:1,Routepath:4-2Time(s):22.000001000,Node:1,Routepath:4-2Time(s):23.000001000,Node:1,Routepath:4-2Time(s):24.000001000,Node:1,Routepath:4-2Time(s):25.000001000,Node:1,Routepath:4-2Time(s):26.000001000,Node:1,Routepath:4-2Time(s):27.000001000,Node:1,Routepath:4-2Time(s):28.000001000,Node:1,Routepath:4-2Time(s):29.000001000,Node:1,Routepath:4-2Time(s):30.000001000,Node:1,Routepath:4-2Time(s):31.000001000,Node:1,Routepath:4-2Time(s):32.000001000,Node:1,Routepath:4-2Time(s):33.000001000,Node:1,Routepath:4-2Time(s):34.000001000,Node:1,Routepath:4-2Time(s):35.000001000,Node:1,Routepath:4-2Time(s):36.000001000,Node:1,Routepath:4-2Time(s):37.000001000,Node:1,Routepath:4-2Time(s):38.000001000,Node:1,Routepath:5-4-2Time(s):39.000001000,Node:1,Routepath:5-4-2Time(s):40.000001000,Node:1,Routepath:5-4-2Time(s):41.000001000,Node:1,Routepath:5-4-2Time(s):42.000001000,Node:1,Routepath:5-4-2Time(s):43.000001000,Node:1,Routepath:5-4-2Time(s):44.000001000,Node:1,Routepath:5-4-2Time(s):45.000001000,Node:1,Routepath:5-4-2Time(s):46.000001000,Node:1,Routepath:5-4-2Time(s):47.000001000,Node:1,Routepath:5-4-2Time(s):48.000001000,Node:1,Routepath:5-4-2Time(s):49.000001000,Node:1,Routepath:5-4-2Time(s):50.000001000,Node:1,Routepath:5-4-2Time(s):51.000001000,Node:1,Routepath:5-4-2Time(s):52.000001000,Node:1,Routepath:5-4-2Time(s):53.000001000,Node:1,Routepath:5-4-2Time(s):54.000001000,Node:1,Routepath:5-4-2Time(s):55.000001000,Node:1,Routepath:5-4-2Time(s):56.000001000,Node:1,Routepath:5-4-2Time(s):57.000001000,Node:1,Routepath:5-4-2Time(s):58.000001000,Node:1,Routepath:5-4-2Time(s):59.000001000,Node:1,Routepath:5-4-2Time(s):60.000001000,Node:1,Routepath:5-4-2Time(s):61.000001000,Node:1,Routepath:5-4-2Time(s):62.000001000,Node:1,Routepath:5-4-2Time(s):63.000001000,Node:1,Routepath:5-4-2Time(s):64.000001000,Node:1,Routepath:5-4-2Time(s):65.000001000,Node:1,Routepath:5-4-2Time(s):66.000001000,Node:1,Routepath:5-4-201000,Node:1,Routepath:5-4-2Time(s):68.000001000,Node:1,Routepath:3-2Time(s):69.000001000,Node:1,Routepath:3-2Time(s):70.000001000,Node:1,Routepath:3-2Time(s):71.000001000,Node:1,Routepath:3-2Time(s):72.000001000,Node:1,Routepath:3-2Time(s):73.000001000,Node:1,Routepath:3-2Time(s):74.000001000,Node:1,Routepath:3-2Time(s):75.000001000,Node:1,Routepath:3-2Time(s):76.000001000,Node:1,Routepath:3-2Time(s):77.000001000,Node:1,Routepath:3-2Time(s):78.000001000,Node:1,Routepath:3-2Time(s):79.000001000,Node:1,Routepath:3-2Time(s):80.000001000,Node:1,Routepath:3-2Time(s):81.000001000,Node:1,Routepath:3-2Time(s):82.000001000,Node:1,Routepath:3-2Time(s):83.000001000,Node:1,Routepath:3-2Time(s):84.000001000,Node:1,Routepath:3-2Time(s):85.000001000,Node:1,Routepath:3-2Time(s):86.000001000,Node:1,Routepath:3-2Time(s):87.000001000,Node:1,Routepath:3-2Time(s):88.000001000,Node:1,Routepath:3-2Time(s):89.000001000,Node:1,Routepath:3-2Time(s):90.000001000,Node:1,Routepath:3-2Time(s):91.000001000,Node:1,Routepath:3-2Time(s):92.000001000,Node:1,Routepath:3-2Time(s):93.000001000,Node:1,Routepath:2Time(s):