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发布时间:2023-03-10 19:27

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一篇有关TCP/IP局域网的英文论文

(第一篇)这篇简单介绍了TCP/IP协议。 可供参考。
What is TCP/IP? TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. It can also be used as a communications protocol in a private network (either an intranet or an extranet). When you are set up with direct access to the Internet, your computer is provided with a copy of the TCP/IP program just as every other computer that you may send messages to or get information from also has a copy of TCP/IP.

TCP/IP is a two-layer program. The higher layer, Transmission Control Protocol, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message. The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message. Even though some packets from the same message are routed differently than others, they'll be reassembled at the destination.

TCP/IP uses the client/server model of communication in which a computer user (a client) requests and is provided a service (such as sending a Web page) by another computer (a server) in the network. TCP/IP communication is primarily point-to-point, meaning each communication is from one point (or host computer) in the network to another point or host computer. TCP/IP and the higher-level applications that use it are collectively said to be "stateless" because each client request is considered a new request unrelated to any previous one (unlike ordinary phone conversations that require a dedicated connection for the call duration). Being stateless frees network paths so that everyone can use them continuously. (Note that the TCP layer itself is not stateless as far as any one message is concerned. Its connection remains in place until all packets in a message have been received.)

Many Internet users are familiar with the even higher layer application protocols that use TCP/IP to get to the Internet. These include the World Wide Web's Hypertext Transfer Protocol (HTTP), the File Transfer Protocol (FTP), Telnet (Telnet) which lets you logon to remote computers, and the Simple Mail Transfer Protocol (SMTP). These and other protocols are often packaged together with TCP/IP as a "suite."

Personal computer users with an analog phone modem connection to the Internet usually get to the Internet through the Serial Line Internet Protocol (SLIP) or the Point-to-Point Protocol (PPP). These protocols encapsulate the IP packets so that they can be sent over the dial-up phone connection to an access provider's modem.

Protocols related to TCP/IP include the User Datagram Protocol (UDP), which is used instead of TCP for special purposes. Other protocols are used by network host computers for exchanging router information. These include the Internet Control Message Protocol (ICMP), the Interior Gateway Protocol (IGP), the Exterior Gateway Protocol (EGP), and the Border Gateway Protocol (BGP).

(第二篇)这篇介绍了TCP/IP的发展
Development of TCP/IP

The original research was performed in the late 1960s and early 1970s by the Advanced Research Projects Agency (ARPA), which is the research arm of the US Department of Defense (DOD). The DOD wanted to build a network to connect a number of military sites. The key requirements for the network were as follows:

* It must continue to function during nuclear war (development took place during the 'cold war'). The 7/8th rule required that the network should continue to function even when 7/8th of the network was not operational
* It must be completely decentralized with no key central installation that could be destroyed and bring down the whole network
* It must be fully redundant and able to continue communication between A and B even though intermediate sites and links might stop functioning during the conversation
* The architecture must be flexible as the envisaged range of applications for the network was wide (anything from file transfer to time-sensitive data such as voice)

ARPA hired a firm called BBN to design the network. The prototype was a research network called ARPANET (first operational in 1972). This connected four university sites using a system described as a packet switching network.

Prior to this development, any two computers wanting to communicate had to open a direct channel (known as a circuit) and information was then sent. If this circuit were broken, the computers would stop communicating immediately, which the DOD specifically wanted to avoid.

One computer could forward information to another by using packet-switching, so it superseded circuit-switched networks. To ensure information reached the correct destination, each packet was addressed with a source and destination and the packet was then transferred using any available pathway to the destination computer.

It was divided into small chunks or packets (originally 1008 bits). Sending large chunks of information has always presented problems, often because the full message fails to reach its destination at the first attempt, and the whole message then has to be resent. The facilities within the new protocol to divide large messages into numerous small packets meant that a single packet could be resent if it was lost or damaged during transmission, rather than the whole message.

The new network was decentralized with no one computer controlling its operation where the packet switching protocol controlled most of the network operations.

TCP/IP is a very robust protocol and can automatically recover from any communication link failures. It re-routes data packets if transmission lines are damaged or if a computer fails to respond, utilizing any available network path. The figure below shows an example of an Internet system. A packet being sent from Network A to Network F may be sent via Network D (the quickest route). If this route becomes unavailable, the packet is routed using an alternate route (for example, A B C E F).

Once ARPANET was proven, the DOD built MILNET (Military Installation in US) and MINET (Military Installation in Europe). To encourage the wide adoption of TCP/IP, BBN and the University of California at Berkeley were funded by the US Government to implement the protocol in the Berkeley version of Unix. UNIX was given freely to US universities and colleges, allowing them to network their computers. Researchers at Berkeley developed a program interface to the network protocol called sockets and wrote many applications using this interface.

During the early 1980s, the National Science Foundation (NSF) used Berkeley TCP/IP to create the Computer Science Network (CSNET) to link US universities. They saw the benefit of sharing information between universities and ARPANET provided the infrastructure. Meanwhile, in 1974 a successor to ARPANET was developed named NSFNET. This was based on a backbone of six supercomputers into which many regional networks were allowed to connect.

The first stage in the commercial development of the Internet occurred in 1990 when a group of telecommunications and computer companies formed a non-profit making organization called Advanced Networks and Services (ANS). This organization took over NSFNET and allowed commercial organizations to connect to the system. The commercial Internet grew from these networks.

上述两篇都可供参考。

一、TCP/IP协议簇简介

TCP/IP(传输控制协议/网间协议)是一种网络通信协议,它规范了网络上的所有通信设备,尤其是一个主机与另一个主机之间的数据往来格式以及传送方式。TCP/IP是 INTERNET的基础协议,也是一种电脑数据打包和寻址的标准方法。在数据传送中,可以形象地理解为有两个信封,TCP和IP就像是信封,要传递的信息被划分成若干段,每一段塞入一个TCP信封,并在该信封面上记录有分段号的信息,再将TCP信封塞入IP大信封,发送上网。在接受端,一个TCP软件包收集信封,抽出数据,按发送前的顺序还原,并加以校验,若发现差错,TCP将会要求重发。因此,TCP/IP在INTERNET中几乎可以无差错地传送数据。在任何一个物理网络中,各站点都有一个机器可识别的地址,该地址叫做物理地址.物理地址有两个

特点:

(1)物理地址的长度,格式等是物理网络技术的一部分,物理网络不同,物理地址也不同.

(2)同一类型不同网络上的站点可能拥有相同的物理地址.

以上两点决定了,不能用物理网络进行网间网通讯.

在网络术语中,协议中,协议是为了在两台计算机之间交换数据而预先规定的标准。TCP/IP并不是一个而是许多协议,这就是为什么你经常听到它代表一个协议集的原因,而TCP和IP只是其中两个基本协议而已。

你装在计算机-的TCP/IP软件提供了一个包括TCP、IP以及TCP/IP协议集中其它协议的工具平台。特别是它包括一些高层次的应用程序和FTP(文件传输协议),它允许用户在命令行上进行网络文件传输。

TCP/IP 是美国政府资助的高级研究计划署(ARPA)在二十世纪七十年代的一个研究成果,用来使全球的研究网络联在一起形成一个虚拟网络,也就是国际互联网。原始的Internet通过将已有的网络如ARPAnet转换到TCP/IP上来而形成,而这个Internet最终成为如今的国际互联网的骨干网。

如今TCP/IP如此重要的原因,在于它允许独立的网格加入到Internet或组织在一起形成私有的内部网(Intranet)。构成内部网的每个网络通过一种-做路由器或IP路由器的设备在物理上联接在一起。路由器是一台用来从一个网络到另一个网络传输数据包的计算机。在一个使用TCP/IP的内部网中,信息通过使用一种独立的叫做IP包(IPpacket)或IP数据报(IP datagrams)的数据单元进--传输。TCP/IP软件使得每台联到网络上的计算机同其它计算机“看”起来一模一样,事实上它隐藏了路由器和基本的网络体系结构并使其各方面看起来都像一个大网。如同联入以太网时需要确认一个48位的以太网地址一样,联入一个内部网也需要确认一个32位的IP地址。我们将它用带点的十进制数表示,如128.10.2.3。给定一个远程计算机的IP地址,在某个内部网或Internet上的本地计算机就可以像处在同一个物理网络中的两台计算机那样向远程计算机发送数据。

TCP/IP 提供了一个方案用来解决属于同一个内部网而分属不同物理网的两台计算机之间怎样交换数据的问题。这个方案包括许多部分,而TCP/IP协议集的每个成员则用来解决问题的某一部分。如TCP/IP协议集中最基本的协议-IP协议用来在内部网中交换数据并且执行一项重要的功能:路由选择--选择数据报从A主机到B主机将要经过的路径以及利用合适的路由器完成不同网络之间的跨越(hop)。

TCP 是一个更高层次的它允许运行在在不同主机上的应用程序相互交换数据流。TCP将数据流分成小段叫做TCP数据段(TCP segments),并利用IP协议进行传输。在大多数情况下,每个TCP数据段装在一个IP数据报中进行发送。但如需要的话,TCP将把数据段分成多个数据报,而IP数据报则与同一网络不同主机间传输位流和字节流的物理数据帧相容。由于IP并不能保证接收的数据报的顺序相一致,TCP会在收信端装配 TCP数据段并形成一个不间断的数据流。FTP和Telnet就是两个非常流行的依靠TCP的TCP/IP应用程序。

另一个重要的TCP/IP协议集的成员是用户数据报协议(UDP),它同TCP相似但比TCP原始许多。TCP是一个可靠的协议,因为它有错误检查和握手确认来保证数据完整的到达目的地。UDP是一个“不可靠”的协议,因为它不能保证数据报的接收顺序同发送顺序相同,甚至不能保证它们是否全部到达。如果有可靠性要求,则应用程序避免使用它。同许多TCP/IP工具同时提供的SNMP(简单网络管理协议)就是一个使用UDP协议的应用例子。

其它TCP/IP协议在TCP/IP网络中工作在幕后,但同样也发挥着重要作用。例如地址转换协议(ARP)将IP地址转换为物理网络地址如以太网地址。而与其对应的反向地址转换协议(RARP)做相反的工作,即将物理网络地址转换为IP地址。网际控制报文协议(ICMP)则是一个支持性协议,它利用IP完成IP数据报在传输时的控制信息和错误信息的传输。例如,如果一个路由器不能向前发送一个IP数据报,它就会利用ICMP来告诉发送者这里出现了问题。

这个不是原版翻译,不过相差不多。

-0-。你先要的是英文版啊~ 囧~ 要不你再发个帖,找人翻译下。

求解答,BGP协议在国内外的概况和研究趋势是怎么样?

BGP原先只是为运营商中域间路由传递而设计的,但是到目前为止,不仅仅是运营商之间,还有很多大企业在接入运营商时,也会选择使用BGP接入方式,这样的好处在于可以细化至路由条目,对其路由进行单一控制,灵活度较高。
目前BGP分为很多地址族,目前在运营商中用的比较多的有ipv4 unicast bgp / ipv6 unicast bgp / vpnv4 bgp / vpnv6 bgp 以及ipv4 mdt bgp(用来传递域间组播VPN路由)。现在国外运营商大部分已经完成了ipv6 bgp与vpnv6 bgp的双栈构建,而国内也在今后2年内完成骨干网ipv6 bgp的建设,在未来几年形成业务接入的格局。

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