国际互联网,始于 1969年的美国,又称因特网,是全球性的网络,是一种公用信息的载体, 是大众传媒的一种。 互联网是由一些使用公用语言互相通信的计算机连接而成的网络, 即广域网、 局域网及单机按照一定的通讯协议组成的国际计算机网络。 组成互联网的计算机 网络包括小规模的局域网(LAN 、城市规模的区域网(MAN 以及大规模的广域网(WAN 等 等。这些网络通过普通电话线、 高速率专用线路、 卫星、 微波和光缆等线路把不同国家的大 学、公司、科研部门以及军事和政府等组织的网络连接起来。
各行各业的人需要运用互联网来工作、生活、娱乐、消费,互联网本身是一个产业,同 时它也带动了其他所有的产业的发展。 计算机网络仅仅是传输信息的媒介, 是一个狭义的硬件网。 而互联网是个广义的网, 它的精华则是它能够为你提供有价值的信息和令人满意的服 务。 互联网也是一个面向公众的社会性组织。世界各地数以万计的人们可以利用互联网进行 信息交流和资源共享。 互联网是人类社会有史以来第一个世界性的图书馆和第一个全球性论 坛。 它为用户提供了高效工作环境, 入网的电脑终端可以调阅各种信息资料。 人民可以通过 互联网进行娱乐与消费,听歌、看视频、购物。随着通讯技术的发展,上网终端已经不限于 台式电脑和移动电脑,智能手机、平板电脑、掌上游戏机,甚至谷歌开发出来的眼镜、手表 都可以上网。网络无处不在,网络无所不能。
一、从互联网的发展历程来看,从最初的ARPANET 到如今的万维网。
1、互联网的起源。这一时期推动互联网发展的推动力是美国的冷战思维。
作为对前苏联 1957年发射的第一颗人造地球卫星 Sputnik 的直接反应,以及由苏联的 卫星技术潜在的军事用途所导致的恐惧, 美国国防部组建了高级研究项目局 (ARPA 。 当时, 美国国防部为了保证美国本土防卫力量和海外防御武装在受到前苏联第一次核打击以后仍 然具有一定的生存和反击能力, 认为有必要设计出一种分散的指挥系统:它由一个个分散的 指挥点组成,当部分指挥点被摧毁后,其它点仍能正常工作, 并且这些点之间,能够绕过那 些已被摧毁的指挥点而继续保持联系。为了对这一构思进行验证, 1969 美国国防部委托开 发 ARPANET ,进行联网的研究。同年,美军在 ARPA 制定的协定下将美国加利福尼亚大学、 斯坦福大学研究学院加利福尼亚大学和犹他州大学的四台主要的计算机连接起来。这个协定 由剑桥大学的 BBN 和 MA 执行,在 1969年 12月开始联机。它的目的就是重新树立美国在军事科技应用开发方面的领导地位。当时的网络传输能力只有 50Kbps ,按标准来说就是非常 的低。
从 1970年开始, 加入 ARPANET 的节点数不断的增加。 当时 ARPANET 使用的是 NCP 协议, 它允许计算机相互交流,从 1970年开始,加入 ARPANET 的节点数不断的增加。最初的 NCP 协议下的 ARPANET 上连接了 15个节点共 23台主机。到 1972年时, ARPANET 网上的网点数 已经达到 40个,这 40个网点彼此之间可以发送小文本文件(当时称这种文件为电子邮件, 也就是我们现在的 E-mail 和利用文件传输协议发送大文本文件,包括数据文件(即现在 Internet 中的 FTP
,同时也发现了通过把一台电脑模拟成另一台远程电脑的一个终端而使 用远程电脑上的资源的方法, 这种方法被称为 Telnet 。 由此可看到, E-mail , FTP 和 Telnet 是 Internet 上较早出现的重要工具, 特别是 E-mail 仍然是目前Internet 上最主要的应用。 但在 NCP 协议下,目的地之外的网络和计算机却不分配地址,从而限制了未来增长的机会。 但无论如何, ARPANET 成为了第一个简单的纯文字系统的 Internet 。可以说,最早促使互 联网最初起源的推动力是冷战时期的军备角力思维。
2、 TCP/IP协议的产生。
由于最初的通信协议下对于节点以及用户机数量的限制,建立一种能保证计算机之间进行通信的标准规范(即“通信协议” 显得尤为重要。 1973年,美国国防部也开始研究如何实现各种不同网络之间的互联问题。作为 Internet 的早期骨干网,
ARPAnet 的试验并奠 定了 Internet 存在和发展的基础, ARPAnet 在技术上的另一个重大贡献是 TCP/IP协议簇的
开发和利用。 1972年 Robert
Kahn来到 ARPA ,并提出了开放式网络框架,从而出现了大家熟知的 TCP/IP(传输控制协议 /网际协议 。 1983年 1月 1日,所有连入 ARPANET 的主机实 现了从 NCP 向 TCP/IP协议的转换。为了将这些网络连接起来,美国人温顿•瑟夫(Vinton
Cerf 提出一个想法:在每个网络内部各自使用自己的通讯协议,在和其它网络通信时使用 TCP/IP协议。
这个设想最终导致了 Internet 的诞生,并确立了 TCP/IP协议在网络互联方面不可动 摇的地位,基于 TCP/IP协议的公网的发展推动了互联网的发展。
3、网络的“春秋战国”时代。
70年代末到 80年代初,可以说是网络的春秋战国时代,各种各样的网络应运而生。 八十年代初, DARPANet 取得了巨大成功,但没有获得美国联邦机构合同的学校仍不能使用。为解决这一问题,美国国家科学基金会(NSF 开始着手建立提供给各大学计算机系使用的计算机科学网(CSNet 。 CSNet 是在其他基础网络之上加统一的协议层,形成逻辑上 的网络,它使用其他网络提供的通信能力,在用户观点下也是一个独立的网络。 CSNet 采用 集中控制方式,所有信息交换都经过 CSNet-Relay (一台中继计算机进行。
1982年,美国北卡罗莱纳州立大学的斯蒂文•贝拉文(Steve Bellovin 创立了著名的 集电极通信网络——网络新闻组 (Usenet , 它允许该网络中任何用户把信息 (消息或文章 发送给网上的其他用户,大家可以在网络上就自己所关心的问题和其他人进行讨论; 1983年在纽约城市大学也出现了一个以讨论问题为目的的网络—— BITNet , 在这个网络中, 不同 的话题被分为不同的组, 用户可以根据自己的需求, 通过电脑订阅, 这个网络后来被称之为Mailing List (电子邮件群 ; 1983年,在美国旧金山还诞生了另一个网络 FidoNet (费多 网或 Fido BBS即公告牌系统。它的优点在于用户只要有一部电脑、一个调制解调器和一根电话线就可以互相发送电子邮件并讨论问题,这就是后来的 Internet
BBS。
以上这些网络都相继并入 Internet 而成为它的一个组成部分, 具有特定用途和特点的 网络的发展,推动了 Internet 成为全世界各种网络的大集合。
4、 Internet 的基础—— NSFNET
Internet 的第一次快速发展源于美国国家科学基金会(National Science Foundation 简称 NSF 的介入,即建立 NSFNET 。
1983年, ARPAnet 分裂为两部分, ARPAnet 和纯军事用的 MILNET 。八十年代初,美国 一大批科学家呼吁实现全美的计算机和网络资源共享, 以改进教育和科研领域的基础设施建设,抵御欧洲和日本先进教育和科技进步的挑战和竞争。
80年代中期,美国国家科学基金会(NSF 为鼓励大学和研究机构共享他们非常昂贵的 四台计算机主机,希望各大学、研究所的计算机与这四台巨型计算机联接起来。最初 NSF 曾试图使用 DARPANet 作 NSFNET 的通信干线,但由于DARPANet 的军用性质,并且受控于政 府机构,这个决策没有成功。于是他们决定自己出资,利用 ARPANET 发展出来的TCP/IP通 讯协议,建立名为 NSFNET 的广域网。
Internet 在 80年代的扩张不单带来量的改变, 同时亦带来某些质的变化。 由于多种学术 团体、企业研究机构,甚至个人用户的进入, Internet 的使用者不再限于纯计算机专业人员。 新的使用者发觉计算机相互间的通讯对他们来讲更有吸引力。于是,他们逐步把 Internet 当 作一种交流与通信的工具,而不仅仅只是共享 NSF 巨型计算机的运算能力。 NSFnet 对 Internet 的最大贡献是使 Internet 向全社会开放, 而不象以前的那样仅供计算机研究人员和 政府机构使用。更多的非计算机专业人员希望通过使用广域网得到他们希望得到的信息。 5、中国互联网的发展。
1987年 9月 20日,钱天白教授发出我国第一封电子邮件“越过长城,通向世界” ,揭开了中国人使用 Internet 的序幕。 1990年 10月,钱天白教授代表中国正式在国际互联网
络信息中心的前身 DDN-NIC (相当于现在的 INTERNIC 注册登记了我国的顶级域名 CN ,并 且从此开通了使用中国顶级域名 CN 的国际电子邮件服务,因特网在我国进入了飞速发展时 期。 1996年 1月, ChinaNET 全国骨干网建成并正式开通,全国范围的公用计算机互联网络 开始提供服务。
截至 2010年 6月,中国网民规模达到 4.2亿,大部分网络应用在网民中更加普及,各 类网络应用的用户规模持续扩大。其中, 商务类应用表现尤其突出,网上支付、网络购物和 网上银行半年用户增长率均在 30%左右,远远超过其他类网络应用。社交网站、网络文学和 搜索引擎用户增长也较快。 截至 2010年 6月, 网络购物、 网上支付和网上银行的使用率分 别为 33.8%、 30.5%和29.1%,增速在各类应用中排名前三。网络购物在主要网络应用中排 名提升一位,使用率超过了论坛。从 2010开始互联网彻底走进人们的生活。通讯电子产品 价格的急剧下降,导致笔记本,台式电脑,智能手机的广泛普及使得上网变得更加简单。 二、从技术的角度来看,从包交换、通信协议以及组网的规模一直都是科学家和通信 工作者们研究与努力的方向。这些技术层面的不断突破,促进了互联网的发展。
1、利用 TCP/IP协议代替 NCP 协议。
最初 BBN 公司设计、组装并运行了ARPANET 。 1969年就有了一个充分发展了的包交 换网络。 BBN 建造了一个多处理器的系统一 Pluribus , 许多软件开发后来又被用在 ARPANET 上。那时, TCP /IP 还在早期阶段, IETF 的科学家所做的是将 TCP /IP 引入 TIP ,而 TIP 又是 IMP 的一部分。项目中的一个步骤就是用 TCP /IP 协议代替 ARPANET 原来的主机到 主机的协议 NCP 。
2、用多层的路由分配来解决路由表限制的问题。
起初要建造一些被称作网关的东西 (现在叫做路由 。当时能够意识到路由器本身就可以作为分组交换机,这是一个很激进的想法, BBN 里大行其道的还是 ARPANET 风格的分组 交换, 而这在商业上追根溯源是来自 X . 25包交换。 BBN 的工作人员们认为 IP 和路由并不 可靠。 科学家们花费了很大力气才说服他们这是一个重要的商机。 此后,科学小组研发并部 署了四代网关/路由器、 Hw 、 SW 等等。有很多问题至今还在讨论中,比如路由表变得太 大。然后有了试图区分内部路由和外部路由的想法。早先有一个协议,然后取而代之的是 BGP(边界网关协议 。为了完成这项工作, BBN 定期举行会议—开始是为了ARPA ,后来是 为了防御数据网 (DefenseDatanetwork。这一切都在 IETF 之前,作为一项规范化制定协议的 活动,后来才发展成为了 IETF 。
3、随着 IETF 的设立与发展壮大,下一代的 IP 协议:IPV6的诞生。
IETF ,互联网工程任务组,成立于 1985年底,是全球互联网最具权威的技术标准化组 织, 主要任务是负责互联网相关技术规范的研发和制定, 当前绝大多数国际互联网技术标准出自 IETF 。随着 IETF 的发展壮大,第二任主席 PhilGross 决定按不同领域划分 IETF 。由于 在 BBN 时路由方面的工作, Bob Hinton受任为第一任路由区域主管 (AreaDirector, 简称 AD 。 IETF 建立并统一了现存的所有路由协议:RIPv2、 OsPF 、 IS —
IS 、 BGP 。引人注目的是,那 时建立的一些工作组至今还在继续工作。 Bob 的小组参与了 IPng 过程的工作,和另一个组 合作 (和SteveDeering 起 ,研发了下一个版本的 IP ——
IPv6。
互联网之所以能有今天的发展,有两个因素功不可没:
一是 IP 和 TCP 简单易用的接口,二是设备之间无需有十分紧密的联系。 这样一来, 不同的公司、组织、 不同的人都可以参与建设互联网。要想建立不仅技术上可行、同时商业 环境上友好的网络, 这是唯一的途径:各自为政, 没有人独揽大权。联系过于紧密的事物是 难以测度的。 一个相反的例子就是电话网络最初的发展。 在美国和许多其他国家, 都有一个 组织包揽建网、 设立标准、技术研发的全部工作。 互联网从未按照这种模式发展。 从一开始 大家就各自为政,十分灵活。这是互联网之所以成长壮大并如此多样的原因之一。
未来的互联网仅仅靠现有的笔记本电脑、 PC 和服务器是不够的,越来越多的小型器件 和植入型的器件将会出现。这些设备可能是自组的,但它们相互联网。建造如此庞大、 复杂 并且密集的网络, 一切都要达到互联, 并且在一个安全的方式下实现交互, 这就是我们通常 所说的物联网。这些都还需要我们长时间的努力。TheInternet, started in 1969 in the United States, also known as the Internet, isa global network, is a carrier of public information, is a kind of mass media.The Internet is a network of computers that communicate with each other using acommon language, namely a wide area network, local area network and a singleinternational computer network composed of certain communication protocols. Thecomputer networks that make up the Internet include small-scale local areanetworks (Lans), city-scale area networks (MAN), and large-scale wide areanetworks (WAN, etc. These networks connect the networks of universities,companies, research departments, military and government organizations indifferent countries through regular telephone lines, high-speed private lines,satellites, microwave and optical cables.
People from all walks of life need to usethe Internet to work, live, play and consume. The Internet itself is anindustry, and at the same time, it also drives the development of all otherindustries. Computer network is only the transmission of information medium, isa narrow sense of hardware network. While the Internet is a broad network, itsessence is that it can provide you with valuable information and satisfactoryservices. The Internet is also a social organization facing the public.Millions of people around the world can use the Internet to exchangeinformation and share resources. The Internet is the first worldwide libraryand the first global forum in the history of human society. It provides anefficient working environment for users, and the computer terminal connected tothe network can access all kinds of information. People can use the Internetfor entertainment and consumption, listening to music, watching videos andshopping. With the development of communication technology, Internet accessterminals are no longer limited to desktop computers and mobile computers.Smart phones, tablets, handheld game consoles, and even glasses and watchesdeveloped by Google can also access the Internet. The Internet is everywhere.The Internet can do anything.
First, from the development process of theInternet, from the original ARPANET to today's World Wide Web.
1. The origin of the Internet. The impetusfor the development of the Internet in this period was the Cold War mentalityof the United States.
In direct response to the launch ofSputnik, the Soviet Union's first artificial Earth satellite, in 1957, and tofears about the potential military uses of Soviet satellite technology, theU.S. Department of Defense created the Advanced Research Projects Agency(ARPA). At that time, the department of defense to ensure that the UnitedStates defense force and overseas defense forces in the former Soviet union forthe first time after a nuclear strike but still has a certain ability ofsurvival and countering think it necessary to design a decentralized commandsystem: it is composed of discrete point of command, when part of the commandis destroyed, other points can still work normally, And these points are ableto keep in touch with each other, bypassing the command points that have beendestroyed. To test the idea, the U.S. Department of Defense commissioned thedevelopment of ARPANET in 1969 to conduct networking research. That same year,the U.S. military connected four major computers at the University ofCalifornia, the Stanford University Research Institute of California, and theUniversity of Utah under an ARPA agreement. This AGREEMENT, implemented by THEBBN AND MA of Cambridge University, became online IN December 1969. Its aim isto reassert America's leadership in the development of military technologyapplications. At the time, the network's transmission capacity was only 50Kbps,which was very low by standards.
Since 1970, the number of nodes added toARPANET has increased continuously. At that time, ARPANET used the NCPprotocol, which allowed computers to communicate with each other. Since 1970,the number of nodes added to ARPANET has been increasing. The original ARPANETunder the NCP protocol was connected to 15 nodes with 23 hosts. By 1972, theARPANET network had 40 outlets that could send small text files (then callede-mails) to each other. We now have E-mail and the use of file transferprotocols to send large text files, including data files (now known as FTP onthe Internet), and we have also discovered ways to use resources on remotecomputers by simulating one computer as a terminal on another remote computer.This method is called Telnet. It can be seen that E-mail, FTP and Telnet arethe important tools that appeared earlier on the Internet, especially E-mail isstill the most important application on the Internet. But under NCP, networksand computers outside the destination are not assigned addresses, limitingopportunities for future growth. However, ARPANET became the first simpletext-only Internet. It can be said that the first driving force for the initialorigin of the Internet is the Cold War armaments wrestling thinking.
2. Generation of TCP/IP protocol.
Due to the limitation of the number ofnodes and user machines under the original communication protocol, it is veryimportant to establish a standard specification (communication protocol) thatcan ensure the communication between computers. In 1973, the U.S. Department ofDefense also began to study how to realize the interconnection between variousnetworks. As the early backbone of Internet, ARPAnet's experiment laid thefoundation for the existence and development of Internet. Another significantcontribution of ARPAnet in technology is TCP/IP protocol cluster
Development and utilization. In 1972 RobertKahn came to ARPA and proposed the open network framework, which led to theTransmission Control Protocol (TCP/IP). On January 1, 1983, all hosts connectedto ARPANET implemented the conversion from NCP to TCP/IP. To connect thesenetworks, Vinton Cerf, an American, came up with the idea of using its ownprotocol within each network and TCP/IP to communicate with others.
This idea eventually led to the birth ofthe Internet, and established the TCP/IP protocol in the networkinterconnection of the unshakeable position, based on the development of theTCP/IP protocol of the public network to promote the development of theInternet.
3, the "Spring and Autumn and WarringStates" era of the network.
From the late 1970s to the early 1980s, itcan be said that the Spring and Autumn period of the Internet and the WarringStates period, various networks emerged at the historic moment. In the early1980s, DARPANet was a huge success, but schools without contracts from U.S.federal agencies were still not allowed to use it. To solve this problem, theNational Science Foundation (NSF) has begun to build a Computer Science Network(CSNet) for use by university computer departments. CSNet is a logical networkby adding a unified protocol layer on top of other basic networks. It uses thecommunication capabilities provided by other networks and is an independentnetwork from the user's point of view. CSNet adopts centralized control mode,and all information exchange is carried out by CSNet-relay computer.
In 1982, Steve Bellovin of North CarolinaState University founded Usenet, a famous collector communication network. Itallows any user in the network to send information (messages or articles) toother users on the network, where people can discuss their concerns withothers; In city university of New York in 1983 also appeared a to discuss theproblem for the purpose of Internet, BITNet, in this network, different subjectis divided into different groups, the user can according to their ownrequirements, through the computer to subscribe to, the network became known asMailing List (email group; In 1983, another network, FidoNet, was born in SanFrancisco. Its advantage was that users with only a computer, a modem, and atelephone line could send e-mails to each other and discuss problems, whichbecame Internet BBS.
These networks have been incorporated intothe Internet and become a part of it, with a specific purpose andcharacteristics of the development of the network, promoted the Internet tobecome a large collection of all kinds of networks around the world.
4, the basis of the Internet - NSFNET
The first rapid development of the Internetcame from the intervention of the National Science Foundation (NSF) in theUnited States, namely the establishment of NSFNET.
In 1983, ARPAnet was split into two parts,ARPAnet and the purely military MILNET. In the early 1980s, a large number ofscientists in the United States called for the sharing of computer and networkresources throughout the United States to improve the infrastructureconstruction of education and research, and to resist the challenge andcompetition of advanced education and technological progress in Europe andJapan.
In the mid-1980s, America's NationalScience Foundation (NSF), to encourage universities and research institutionsto share their very expensive four mainframe computers, wanted them to belinked to the four supercomputers. Initially, NSF tried to use DARPANet as theNSFNET communication backbone, but due to the military nature of DARPANet andthe control of government agencies, this decision was unsuccessful. They decidedto fund their own network, called NSFNET, using the TCP/IP communicationprotocol developed by ARPANET.
The expansion of the Internet in the 1980snot only brought about quantitative changes, but also some qualitative changes.Due to the entry of various academic groups, enterprise research institutions,and even individual users, the users of the Internet are no longer limited topure computer professionals. New users find communication between computersmore attractive to them. As a result, they began to use the Internet as a toolfor communication and not just for sharing the computing power of the NSFsupercomputers. NSFnet's greatest contribution to the Internet is to open it upto the whole society, rather than just computer researchers and governmentagencies as before. More non-computer professionals want to get the informationthey want by using wide area NETWORKS. 5. The development of the Internet inChina.
On September 20, 1987, Professor QianTianbai sent China's first E-mail "Beyond the Great Wall, to theworld", which opened the prelude to the use of Internet by the Chinesepeople. In October 1990, Professor Qian Tianbai represented China officially onthe Internet
The predecessor of the Network InformationCenter, DDN-NIC (equivalent to the present INTERNIC), registered our country'stop-level domain name (CN), and since then opened the international E-mailservice using China's top-level domain name (CN). The Internet has entered aperiod of rapid development in China. In January 1996, ChinaNET nationalbackbone network was completed and officially opened, and the nationwide publiccomputer Internet network began to provide services.
By June 2010, the number of Internet usersin China had reached 420 million, and most Internet applications have becomemore popular among them. The number of users of all kinds of Internetapplications has continued to expand. Among them, the performance of businessapplications is particularly outstanding. The growth rate of online payment,online shopping and online banking users is about 30% in half a year, farexceeding other types of Internet applications. Social networking sites, onlineliterature and search engines are also growing fast. As of June 2010, the usagerates of online shopping, online payment and online banking were 33.8%, 30.5%and 29.1% respectively, ranking the top three among all types of applications.Online shopping has moved up one spot in the list of major web applications,surpassing forums in usage. Since 2010, the Internet has come into people'slives. A sharp drop in the price of telecommunications electronics has led towidespread use of laptops, desktop computers and smart phones, making it easierto surf the Internet. Second, from the perspective of technology, packetswitching, communication protocols and the scale of networking have always beenthe direction of research and efforts of scientists and communication workers.These technological breakthroughs have promoted the development of theInternet.
1. Use TCP/IP instead of NCP.
Originally BBN designed, assembled, andoperated the ARPANET. By 1969 there was a fully developed packet switchingnetwork. BBN built Pluribus, a multiprocessor system, and much of the softwaredevelopment was later used in ARPANET. At that time, TCP /IP was still in itsearly stages, and what the IETF scientists did was introduce TCP /IP into TIP,which in turn was part of IMP. One of the steps in the project was to replaceARPANET's original host-to-host protocol, NCP, with TCP /IP.
2. Multi-layer route allocation is used tosolve the problem of routing table restriction.
At first something called a gateway (nowcalled a route) was built. It was a radical idea to realize that routers couldact as packet switches in their own right, and the Arpanet-style packetswitching that was popular in BBN was commercially traced back to X.25 packetswitching. The BBN staff felt that IP and routing were unreliable. Thescientists had a hard time convincing them that this was a major businessopportunity. Since then, the scientific team has developed and implemented fourgenerations of gateways/routers, Hw, SW, etc. There are a number of issues thatare still being discussed, such as routing tables becoming too large. Then camethe idea of trying to distinguish between internal and external routes. Therewas a protocol, and then it was replaced by BGP(Border Gateway Protocol). Toaccomplish this, the BBN held regular meetings -- first for ARPA, then forDefenseDatanetwork. This all predates the IETF as a formalized protocol-makingactivity that later evolved into the IETF.
3, with the establishment and developmentof IETF, the next generation of IP protocol :IPV6 was born.
The IETF, the Internet Engineering TaskForce, was established in 1985