a基于网络的虚拟实验平台—vlp2p通信库的设计与实现

基于网络的虚拟实验平台VLP2P通信库的设计与实现摘要随着信息技术的发展，网络无疑为我们带了更多的便利，因此一个好的系统要具有网络功能。针对虚拟实验台系统的实际功能，采用P2P技术作为其网络通讯基础具有很大的优势降低服务器资源占用，提高通讯传输效率。但由于NAT的广泛使用，使得不同的内网间系统通讯比较困难。希望P2P通讯具有实用价值,穿透NAT实现不同内网间的系统通讯是一个需要解决的重要问题。在基于网络的虚拟实验平台中，有很多功能涉及到网络通讯，为了提高系统的模块化程度，减少系统重复开发量，将网络通信部分独G12447G1998G7481，G16786G16757实现G2529为G57G47P2P的P2P通讯G5223。G16786G16757中，G1075G16786G16757了通讯G5223的G8991G16809程G5219。G13475实际G8991G16809，基G7424G17810到G20056G7411G16786G16757G11458G7643。关键词虚拟实验平台G727P2P技术G727G56G39PG727穿透NATG727G54G70G82G78G72G87G13546程NETWORKBASEDVIRTUALEXPERIMENTALPLATFORMDESIGNANDIMPLEMENTATIONOFVLP2PCOMMUNICATIONLIBRARYABSTRACTWITHTHEDEVELOPMENTOFINFORMATIONTECHNOLOGY,NETWORKSWILLPROVIDEUSWITHMORECONVENIENCEUNDOUBTEDLYTHEREFORE,AGOODSYSTEMMUSTHAVENETWORKFUNCTIONSACCORDINGTOREALFUNCTIONSOFTHEVIRTUALEXPERIMENTPLATFORM,P2PTECHNOLOGYHASPOWERFULBENEFITSTODECREASEPROBABILITYOFUSINGSERVERRESOURCESANDUPGRADETHETRANSMISSIONEFFICIENCY,ASABASEOFNETWORKINGCOMMUNICATIONWHILE,BECAUSEOFTHEEXISTENCEOFNATISSUES,ITISDIFFICULTTOCOMMUNICATEAMONGDIFFERENTLOCALNETWORKSTOMAKEP2PCOMMUNICATIONGETVALUESINREALAPPLICATION,ANIMPORTANTPROBLEMREQUIREDTOSOLVEISTHESYSTEMCOMMUNICATIONAMONGDIFFERENTNETWORKSBYPENETRATINGNATTHEREAREMANYFUNCTIONSRELATEDTONETWORKCOMMUNICATIONINTHEVIRTUALEXPERIMENTPLATFORMBASEDONNETWORKFORIMPROVEMODULARIZATIONOFTHESYSTEMANDDECREASEREPETITIVEDEVELOPINGWORK,THENETWORKCOMMUNICATIONISEXTRACTEDASANINDEPENDENTPARTTODESIGNANDIMPLEMENTP2PCOMMUNICATIONLIBRARYNAMEDVLP2PINTHETHESIS,THETESTINGPROGRAMFORCOMMUNICATIONLIBRARYISALSODESIGNEDWITHREALTESTAMENT,ITHASPROVENTHATTHECOMMUNICATIONLIBRARYHASACHIEVEDTHEINITIALPURPOSEKEYWORDSVIRTUALEXPERIMENTPLATFORMP2PTECHNOLOGYUDPPENETRATINGNATSOCKETPROGRAMMING目录G16782G7003G5647G20041G69802G19G200411A2A01A4A1A4A1A6A3A5A71A4A1A8A1A6A3A9A101A4A1A8A1A4A13A11A12A14A15A161A4A1A8A1A8A15A16A17A18A19A201A4A1A21A1A22A23A24A251A26A27A28A27A26A29A30A24A251A26A27A28A27A31A32A33A34A35A36A33A342A26A27A28A27A28A37A38A39A40A41A42A432A26A27A44A27A22A23A45A46A47A48A49A50A512A26A27A44A27A26A52A53A54A55A56A572A26A27A44A27A31A36A58A59A60A61A62A63A64A41A37A38A56A5722A65A66A67A68A69A70A71A722A31A27A26A27A34A73A36A74A75A76A77A782A31A27A31A27A53A31A53A65A66A79A71A80A81A82A83A84A85A86A87A88A83A81A85A82A8933A22A23A65A66A37A38A41A90A91A92A783A28A27A26A27A93A94A76A41A95A96A67A97A98A993A28A27A31A27A37A38A92A784A28A27A28A27A37A38A92A78A100A10174A90A91A102A103A47A104A105A106A79A717A44A27A26A27A78A107A108A24A29A30A71A727A44A27A31A27A108A24A102A103A71A727A44A27A28A27A26A109A110A111A112A113A92A78A108A24A102A1037A44A27A28A27A31A114A115A116A117A118A92A78A108A24A102A1038A44A27A28A27A28A119A120A90A121A122A97A123A114A115A116A108A24A102A103A1248A44A27A28A27A44A119A120A90A121A122A97A123A109A110A111A116A108A24A102A103A1248A44A27A28A27A125A53A31A53A119A120A90A121A122A97A123A114A115A116A108A24A102A103A1249A44A27A28A27A126A114A115A116A53A31A53A119A120A90A121A122A97A123A109A110A111A116A108A24A102A103A12410A44A27A28A27A105A106A127A12812A44A27A28A27A26A129A130A109A110A47A114A115A116A131A13212A44A27A28A27A31A37A92A109A110A111A119A120A90A121A122A9713433A133A134A117A11814A101A13514A136A137A122A13814A139A14016A141A142A143A144A143A144A145A145A146A147A148A149A150A146A147A148A149A146A151A152A153A143A144A143A144A145A145A146A147A148A149A150A146A147A148A149A146A151A1541A155A15620A1551引言INTERNETG17839G15904G16787问。NAT技术G2499G1209为TCPG451UDPG1209及ICMP的部分信息G17839G15904透G7138中G13499。NAT技术具G1319实现G7053G8873是通G17819IPG3332G3348G7156G4568G7481实现IPG3332G3348的复用。NAT网G1863G1817G5415了G17347由器的G16294G14406,G6164有G3818G1998的网络G2265G18129G5529G20047G17347由到NAT网G1863G727同G7691,G6164有由G3818网发G5460内网的网络G2265G1075G5529G20047G13475G17819NAT网G1863。NAT网G1863通G17819一G4462的G16280G2029,将由内部网G2533G3818部网发G17877的G6980G6466G2265中的源G3332G3348G7156G4568为一个INTERNETG2524G8873G3332G3348,G13792将由G3818G2533内的G6980G6466G2265中的G11458的G3332G3348G7379G6454G6116G11468G5224的内网IPG3332G3348。NAT网G1863有内网G6521G2487G2656G3818网G6521G2487,其中G3818网G6521G2487G2656INTERNETG11468G17842,G5529G20047G6329有G2524G8873IPG3332G3348,内网G6521G2487G2029G2656内网G11468G17842,G2499G1209分G18209G1231G5859G6363G4462的一个内网IPG3332G3348,一G14336G5785G1929G991,G17837个IPG3332G3348G4613是内部G1039G7438的G21676G16760网G1863。11项目背景随着信息技术的发展，网络无疑为我们带了更多的便利，因此一个好的系统G5529G20047要具有网络功能，G17837个功能不G1177G4628G3507网，G18039G4613G4396在一个穿透NAT的问题，G1288随着P2P技术的G1998现，利用G56G39P实现P2P网络穿G17246NAT的G2375G7114通讯技术，我们不在为此G13792G9914G5712。12项目介绍121虚拟实验平台虚拟实验平台是通G17819G17731G1226G13546程G1235G11507G2520G12193G11017G4388器G1226，G2499G1209G1582G2520G12193G11017G17347实验及G16786G16757G5627实验G451基G7424G11017G17347实验G451G11464G8981G11017G17347G451G1144G8981G11017G17347G451G2172G5589G11017G17347G451G17837G1135功能模块G6116为虚拟平台G994实验G13785之间的桥梁，共同构G6116网上虚拟实验室系统，起到帮助学生完G6116实验G1231务。122平台网络通信实现虚拟实验平台具有网络基G7424功能，实现虚拟实验平台具有网络基G7424功能，客户G7438G2656G1039G7438，客户G7438G2656客户G7438之间的G2375G7114通讯G451G7003G1226的传输。由于采用了最新的P2P穿透NAT的技术，因此G2499G1209实现冲破G4628G3507网的限制，实现G11507正的异G3332G17842G6521，同学G2499G1209在家里利用一台普通的能够上网的PC，G4613能把老师布置的实验作业完G6116，并且，老师G2499G1209通G17819服务器端，了解G17839度G5785G1929，并且G2499G1209适G7114的G6363导其实验。13项目要求131功能要求实现虚拟实验平台具有网络基G7424功能，客户G7438G2656G1039G7438，客户G7438G2656客户G7438之间的G2375G7114通讯G451G7003G1226的传输。A1572A158A15920A158132B/S与C/SG11458前的G17731G1226系统G1319系结构一G14336分为两G12193形式，一G12193为大家G6164熟识的C/S结构，另一G12193为B/S结构。C/S结构，G2375CLIENT/SERVER客户端/服务器结构，通G17819将G1231务G2524理分G18209到CLIENT端G2656SERVER端，降低了系统的通讯开销，G2499G1209G1817分利用两端硬G1226环境的优势。B/S结构，G2375BROWSE/SERVER浏览器/服务器结构，G4613是只安装维护一个服务器，G13792客户端采用浏览器运G15904G17731G1226，G17839G15904浏览G451G16787问G451操作G6980G6466。最初的管理信息系统基G7424上是采用C/S模式开发的，但随着WWW的广泛G5224用，G11458前的管理信息系统已G13475逐渐开始从C/S模式G2533浏览器/服务器B/S模式转变。B/S结构的G17731G1226G6164有的维护G451升级工作G18129只在服务器上G17839G15904，G13792客户端能G12447刻获得最新版G7424的G17731G1226。133通信协议的选择G1039G7438G994客户G7438之间采用TCP协议，保证其G2499靠G5627。客户G7438之间采用UDP非G17842G6521，不G2499靠的通讯协议，G11468对于TCPG7481说，虽然G2499靠G5627不及，但传输效率较高。对于G2375G7114通信的系统，选择UDP，G4613是要保证较高的传输效率。14项目难点及解决方法141IP处理问题由于涉及到G2520G12193G4628G3507网，因此需要处理G2520G12193私有IP的G16787问问题。解决G7053G8873采用NAT技术实现私有G3332G3348转G6454G6116公共有效的G3332G3348。142CLIENT之间的通信问题解决G7053G8873利用服务器的打洞原理后详2网络基础知识介绍21SOCKET编程什么是SG82G70G78G72G87它是使用G7643准G56NIXG7003G1226描述符FILG72DG72SG70RIPG87G82RG2656其它程G5219通讯的G7053式。G56NIX程G5219在执G15904G1231何形式的I/O的G7114候，程G5219是在读或G13785写一个G7003G1226描述符。一个G7003G1226描述符只是一个G2656打开的G7003G1226G11468G1863联的整G6980。但是注G5859后G19766的G16817，G17837个G7003G1226G2499能是一个网络G17842G6521，G41IG41O，管G17959，G13468端，G11925G11436上的G7003G1226或G13785什么其它的G1008G16211。G56NIX中G6164有的G1008G16211G4613是G7003G1226G701G6164G1209，G1332G5831G2656ING87G72RNG72G87上G2047的程G5219通讯的G7114候，G1332将要使用到G7003G1226描述符。G1332G5529G20047理解G2030G6177的G16817。现在G1332G14053G9035中或G16780G1894G1998G17837G7691的G5577G3848G256G18039么我从G2750里得到网络通讯的G7003G1226描述符G2614G257，G17837个问题无G16782G3926何我G18129要G3250G12584G1332利用系统G16855用SG82G70G78G72G87，它A1603A161A16220A161G17832G3250G3883G6521G4395描述符SG82G70G78G72G87DG72SG70RIPG87G82R，然后G1332G1889通G17819它G7481G17839G15904SG72NDG2656RG72G70G89G16855用。G256但是G17G17G17G257，G1332G2499能有很大的疑G5797，G256G3926G7536它是个G7003G1226描述符，G18039么为什么不用一G14336G16855用RG72G68DG2656G90RIG87G72G7481G17839G15904G3883G6521G4395通讯G257。G12584G7708是G256G1332G2499G1209，但是使用SG72NDG2656RG72G70G89G16765G1332更好的G6523制G6980G6466传输。G257G4396在G17837G7691一个G5785G1929在我们的G1002G11040上，有很多G12193G3883G6521G4395。有G39AG53PAING87G72RNG72G87G3332G3348ING87G72RNG72G87G3883G6521G4395，G7424G3332G14422G9869的G17347G5464G2529G56NIXG3883G6521G4395，CCITTG59G172G24G3332G3348G1332G2499G1209将G59G172G24G3883G6521G4395完G1852G5585G11065。G1075G16780在G1332的G56NIXG7438器上G17836有其它的。22P2P网络简介INTRODUCTIONP2P技术源于G4628G3507网共G1151，其G11458G7643是G6925变G1166们通G17819服务器中转G1144G6454G7003G1226的传统G7053式，G17810到G14270由G1144G6454资源的G11458的。IG37G48为P2PG991了G3926G991G4462G1053系统由G14521G5190G1126联协作的G16757G12651G7438构G6116，且G14279少具有G3926G991G10317G5461之一系统G1393G4396于G17805G13548化G708非中G3842式服务器G709G16786G3803的G1039G2172协作，G8611个G6116G2604G11464G6521从其G1194G6116G2604G13792不是从服务器的G2454G994中G2475G11422G727系统中G6116G2604同G7114G6210G9448服务器G994客户端的G16294G14406G727系统G5224用的用户能够G5859识到G5456此的G4396在，构G6116一个虚拟或实际的G13688G1319。P2P网络是G1126联网整G1319G7562构的基础，G1126联网最基G7424的TCP/IP协议并G8821有客户端G2656服务器的G8022G5577，在通讯G17819程中，G6164有的G16786G3803G18129是平G12573的一端。P2P技术G6925变了G256内G4493G257G6164在的G1313置，使其正在从G256中G5527G257G17220G2533G256G17805G13548G257，G1075G4613是说不G1889G3926CG63G54模式将内G4493G4396于G1039要的服务器上，G13792是G4396在G6164有用户的PCG7438上。广G1053的P2P网络将P2P网络G2022分为G13443分G6967式P2P网络G3926G74NG88G87G72LLG68模G3423G451G17241级结G9869式网络G2656G9163G2524式P2P网络G12573大G12879。G7424G7003G6164G16764G16782的通讯技术G4658于G9163G2524式P2P网络，G2520G14422G9869之间G2499G1209G11464G6521G5326G12447G17842G6521，但网络的构G5326需要服务器，通G17819G19610中G16760证，G5326G12447G13046G5353G7438制。但是G17837里的服务器G1177用于G17753助对G12573G14422G9869之间G5326G12447G17842G6521，对G12573G14422G9869之间G11464G6521G17839G15904通信，G17837不同于C/G54模式中的服务器。G3926G3282G20P2P网络传输模G3423G6164G12046A163A164A165A166A165A167A168A169A170A171A1723项目网络通信的实现过程31NAT的一些基本概念NATNG72G87G90G82RG78ADDRG72SSTRG68NSLG68G87G82RS，网络G3332G3348转G6454网络G3332G3348转G6454是在IPG3332G3348G7097G11422G13582G1059的G5785G1929G991G1147生的，它的G1039要G11458的G4613是为了能够G3332G3348重用。NAT分为两大G12879，基G7424的NATG2656NAPTNG72G87G90G82RG78ADDRG72SS/PG82RG87TRG68NSLG68G87G82R。最开始NAT是运G15904在G17347由器上的一个功能模块。最G1820提G1998的是基G7424的NAT，它的G1147生基于G3926G991G1119实一个私有网络G708G3507G709A1734A174A17520A174中的G14422G9869中只有很少的G14422G9869需要G994G3818网G17842G6521。G18039么G17837个G4388网中其实只有少G6980的G14422G9869需要G1852G10711G2819一的IPG3332G3348，其G1194的G14422G9869的IPG3332G3348G5224G16825是G2499G1209重用的。因此，基G7424的NAT实现的功能很G12628G2345，在G4388网内使用一个保G11053的IPG4388网G8585，G17837G1135IP对G3818是不G2499G16277的。G4388网内只有少G6980一G1135IPG3332G3348G2499G1209对G5224到G11507正G1852G10711G2819一的IPG3332G3348。G3926G7536G17837G1135G14422G9869需要G16787问G3818部网络，G18039么基G7424NATG4613负责将G17837个G14422G9869的G4388网内IP转化为一个G1852G10711G2819一的IP然后发G17877G1998去。G708G1863于基G7424的NATG2499G1209G2454看G53G41CG2063G20G70932通信过程另G3818一G12193NAT叫G1582NAPT，从G2529称上我们G1075G2499G1209看得G1998，NAPT不但会G6925变G13475G17819G17837个NATG16786G3803的IPG6980G6466报的IPG3332G3348，G17836会G6925变IPG6980G6466报的TCP/G56G39P端G2487。基G7424NAT的G16786G3803G2499能我们G16277的不多，NAPTG6177是我们G11507正G16764G16782的G1039G16294。G16277G32822NAPT端G2487G7156G4568A176A177A178A179A180A181A182A183A184A185有一个私有网络G20G19G17G17G17，CLIG72NG87A是其中的一台G16757G12651G7438，G17837个网络的网G1863G708一个NATG16786G3803G709的G3818网IP是G20G24G24G1799G172G24G17G20G20G5224G16825G17836有一个内网的IPG3332G3348，比G3926G20G19G17G19G17G19G17G20G19。G3926G7536CLIG72NG87A中的某个G17839程G708G17837个G17839程创G5326了一个G56G39PG54G82G70G78G72G87,G17837个G54G82G70G78G72G87绑G4462G20234端G2487G709G5831G16787问G3818网G1039G7438G208G17G208G20G17G19G173G20的G2023G24端G2487，G18039么G5415G6980G6466G2265通G17819NATG7114会发生什么G1119G5785G2614首G1820NAT会G6925变G17837个G6980G6466G2265的原IPG3332G3348，G6925为G20G24G24G1799G172G24G17G20G20。G6521着NAT会为G17837个传输创G5326一个G54G72SSIG82NG708G54G72SSIG82N是一个抽象的G8022G5577，G3926G7536是TCP，G1075G16780G54G72SSIG82N是由一个G54YNG2265开始，G1209一个G41ING2265结束。G13792G56G39PG2614，G1209G17837个IP的A186A187A188A189A187A188A186A190A190A191A192A190A191A190A192A193A192A194A190A195A190A177A194A196A197A198A186A187A199A199A200A201A202A190A203A179A204A186A190A205A198A197A197A190A191A192A190A191A190A192A193A192A194A190A195A190A177A194A196A197A197A189A190A196A196A192A206A206A192A177A196A192A190A190A195A207A177A193A193A193A189A197A197A178A179A181A190A196A196A192A206A206A192A177A196A192A190A190A197A198A186A187A199A199A200A201A202A190A203A179A204A186A190A205A198A197A197A190A191A192A190A191A190A192A193A192A194A190A195A190A177A194A196A197A197A189A190A193A192A193A192A193A192A190A195A190A177A194A208A189A197A197A209A210A200A187A202A211A179A190A193A192A193A192A193A192A190A195A190A177A194A208A2125A213A21420A213G17837个端G2487的第一个G56G39P开始，结束G2614，呵呵，G1075G16780是几分钟，G1075G16780是几小G7114，G17837要看具G1319的实现了G709并且给G17837个G54G72SSIG82N分G18209一个端G2487，比G392662G19G19G19，然后G6925变G17837个G6980G6466G2265的源端G2487为62G19G19G19。G6164G1209G7424G7481是G708G20G19G17G19G17G19G17G20G20234G208G17G208G20G17G19G173G20G2023G24G709的G6980G6466G2265到了G1126联网上变为了G708G20G24G24G1799G172G24G17G20G2062G19G19G19G208G17G208G20G17G19G173G20G2023G24G709。一旦NAT创G5326了一个G54G72SSIG82N后，NAT会记住62G19G19G19端G2487对G5224的是G20G19G17G19G17G19G17G20的G20234端G2487，G1209后从G208G17G208G20G17G19G173G20发G17877到62G19G19G19端G2487的G6980G6466会被NATG14270G2172的转发到G20G19G17G19G17G19G17G20上。G708注G5859G17837里是说G208G17G208G20G17G19G173G20发G17877到62G19G19G19端G2487的G6980G6466会被转发，其G1194的IP发G17877到G17837个端G2487的G6980G6466将被NAT抛弃G709G17837G7691CLIG72NG87AG4613G994G54G72RG89G72RG54G20G5326G12447G1209了一个G17842G6521。呵呵，上G19766的基础知识G2499能很多G1166G18129知G17959了，G18039么G991G19766是G1863键的部分了。看看G991G19766的G5785G1929，G16277G32823NAPT转发G17819程A215A216A217A218A219A220A221A222A223A224G6521上G19766的例G4388，G3926G7536CLIG72NG87A的原G7481G18039个G54G82G70G78G72G87绑G4462了G20234端G2487的G18039个G56G39PG54G82G70G78G72G87又G6521着G2533另G3818一个G54G72RG89G72RG542发G17877了一个G56G39PG2265，G18039么G17837个G56G39PG2265在通G17819NATG7114会怎么G7691G2614G17837G7114G2499能会有两G12193G5785G1929发生，一G12193是NATG1889次创G5326一个G54G72SSIG82N，并且G1889次为G17837个G54G72SSIG82N分G18209一个端G2487号G708比G392662G19G19G20G709。另G3818一G12193是NATG1889次创G5326一个G54G72SSIG82N，但是不会新分G18209一个端G2487号，G13792是用原G7481分G18209的端G2487号62G19G19G19。A225A226A227A228A226A227A225A229A225A226A227A228A226A227A225A230A229A231A232A229A231A229A232A233A232A216A229A234A229A230A216A235A229A216A231A232A236A237A232A230A238A232A236A234A229A230A216A235A239A239A239A239A240A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A240A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A241A240A239A242A225A226A243A243A244A245A246A229A247A218A241A225A229A248A242A239A242A225A226A243A243A244A245A246A230A247A218A241A225A230A248A242A239A229A231A232A229A231A229A232A233A232A216A229A234A229A230A216A235A239A239A239A229A216A231A232A236A237A232A230A238A232A236A234A229A230A216A235A239A228A229A235A235A232A238A238A232A230A235A232A229A229A234A237A230A233A233A233A228A239A228A229A235A235A232A238A238A232A230A235A232A229A229A234A237A230A233A233A233A228A239A249A245A246A226A217A218A220A229A235A235A232A238A238A232A230A235A232A229A229A239A242A225A226A243A243A244A245A246A229A247A218A241A225A229A248A242A239A242A225A226A243A243A244A245A246A230A247A218A241A225A230A248A242A239A229A231A232A229A231A229A232A233A232A216A229A234A229A230A216A235A239A239A239A229A216A231A232A236A237A232A230A238A232A236A234A229A230A216A235A239A228A229A233A232A233A232A233A232A229A234A229A230A216A250A228A239A228A229A233A232A233A232A233A232A229A234A229A230A216A250A228A239A249A251A244A226A246A252A218A229A233A232A233A232A233A232A229A234A229A230A216A250A2126A213A21420A213前一G12193NAT叫G1582G54YMMG72G87RIG70NAT，后一G12193叫G1582CG82NG72NAT。我们G7411望我们的NAT是第二G12193，呵呵，G3926G7536G1332的NATG2030好是第一G12193，G18039么很G2499能会有很多P2PG17731G1226失灵。G708G2499G1209庆幸的是，现在绝大多G6980的NATG4658于后G13785，G2375CG82NG72NATG709好了，我们看到，通G17819NAT,G4388网内的G16757G12651G7438G2533G3818G17842结是很G4493易的G708NATG11468G5415于透G7138的，G4388网内的G2656G3818网的G16757G12651G7438不用知G17959NAT的G5785G1929G709。但是G3926G7536G3818部的G16757G12651G7438G5831G16787问G4388网内的G16757G12651G7438G4613比较困难了G708G13792G17837正是P2PG6164需要的G709。G18039么我们G3926G7536G5831从G3818部发G17877一个G6980G6466报给内网的G16757G12651G7438有什么办G8873G2614首G1820，我们G5529G20047在内网的NAT上打上一个G256洞G257G708G1075G4613是前G19766我们说的在NAT上G5326G12447一个G54G72SSIG82NG709，G17837个洞不能由G3818部G7481打，只能由内网内的G1039G7438G7481打。G13792且G17837个洞是有G7053G2533的，比G3926从内部某台G1039G7438G708比G3926G2092G17G2068G17G19G17G20G19G709G2533G3818部的某个IP比G39262G209G17237G176G19G17G20发G17877一个G56G39PG2265，G18039么G4613在G17837个内网的NATG16786G3803上打了一个G7053G2533为2G209G17237G176G19G17G20的G256洞G257，G708G17837G4613是称为G56G39PHG82LG72PG88NG70HING74的技术G709G1209后2G209G17237G176G19G17G20G4613G2499G1209通G17819G17837个洞G994内网的G2092G17G2068G17G19G17G20G19联系了。G708但是其G1194的IP不能利用G17837个洞G709。呵呵，现在G16825轮到我们的正题P2P了。有了上G19766的理G16782，实现两个内网的G1039G7438通讯G4613差最后一步了G18039G4613是鸡生蛋G17836是蛋生鸡的问题了，两G17805G18129无G8873G1039G2172发G1998G17842G6521请求，谁G1075不知G17959谁的公网G3332G3348，G18039我们G3926何G7481打G17837个洞G2614我们需要一个中间G1166G7481联系G17837两个内网G1039G7438。现在我们G7481看看一个P2PG17731G1226的G8981程，G1209G991G3282为例A215A250A253A230A253A254A255A223A224首G1820，CLIG72NG87A登录服务器，NATA为G17837次的G54G72SSIG82N分G18209了一个端G24876G19G19G19G19，G18039么G54G72RG89G72RG54收到的CLIG72NG87A的G3332G3348是2G192G17G2087G174G24G1736G19G19G19G19，G17837G4613是CLIG72NG87A的G3818网G3332G3348了。同G7691，CLIG72NG87G37登录G54G72RG89G72RG54，NATG37给此次G54G72SSIG82N分G18209的端G2487是4G19G19G19G19，G18039么G54G72RG89G72RG54收到的G37的G3332G3348是G2087G1734G17G20G17G2464G19G19G19G19。此G7114，CLIG72NG87AG994CLIG72NG87G37G18129G2499G1209G994G54G72RG89G72RG54通信了。G3926G7536CLIG72NG87AA30A0A1A2A0A1A30A103A10A3A4A5A10A6A7A5A8A9A5A3A104A142A142A151A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A151A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A146A151A142A142A74A11A12A11A13A154A14A46A15A16A10A9A10A5A3A17A7A5A38A18A5A6A19A74A11A12A20A13A154A14A46A15A16A3A17A7A5A6A38A5A3A5A18A8A19A142A13A155A14A46A15A16A3A4A10A5A3A8A17A5A9A5A3A19A142A13A155A14A46A15A16A3A4A10A5A3A8A17A5A9A5A3A19A142A142A32A21A22A0A23A24A11A13A3A4A10A5A3A8A17A5A9A5A10A9A16A38A9A9A9A19A32A21A22A0A23A24A20A13A3A4A10A5A3A8A17A5A9A5A3A9A16A38A9A9A9A9A19A1257A126A12720A126此G7114G5831G11464G6521发G17877信息给CLIG72NG87G37，G18039么G1194G2499G1209从G54G72RG89G72RG54G18039儿获得G37的公网G3332G3348G2087G1734G17G20G17G2464G19G19G19G19，是不是CLIG72NG87AG2533G17837个G3332G3348发G17877信息CLIG72NG87G37G4613能收到了G2614G12584G7708是不G15904，因为G3926G7536G17837G7691发G17877信息，NATG37会将G17837个信息丢弃G708因为G17837G7691的信息是不请G14270G7481的，为了安G1852，大多G6980NATG18129会执G15904丢弃G2172作G709。现在我们需要的是在NATG37上打一个G7053G2533为2G192G17G2087G174G24G173G708G2375CLIG72NG87A的G3818网G3332G3348G709的洞，G18039么CLIG72NG87A发G17877到G2087G1734G17G20G17G2464G19G19G19G19的信息,CLIG72NG87G37G4613能收到了。G17837个打洞命令由谁G7481发G2614，呵呵，G5415然是G54G72RG89G72RG54。33通信过程总结G5647结一G991G17837个G17819程G3926G7536CLIG72NG87AG5831G2533CLIG72NG87G37发G17877信息，G18039么CLIG72NG87A发G17877命令给G54G72RG89G72RG54，请求G54G72RG89G72RG54命令CLIG7