以太网已经 50 岁了，斩获 IEEE 里程碑称号
局域网 以太网
![](/data/attachment/album/202311/19/094328gprznvlpkrncyzml.png)



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> 这项技术已经成为全球标准的局域网。
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美国加利福尼亚州的[施乐](https://www.xerox.com/en-us)<ruby> <a href="https://spectrum.ieee.org/xerox-parc">  帕洛阿尔托研究中心 </a> <rt>  Palo Alto Research Center </rt></ruby>（PARC）创新无数，诞生了诸如 <ruby> <a href="https://spectrum.ieee.org/xerox-alto">  阿尔托计算机 </a> <rt>  Alto Computer </rt></ruby>（最早采用图形用户界面的个人电脑）及首台激光打印机等多项开创性计算机技术。


同时，PARC 也因发明 <ruby> <a href="https://ethw.org/Ethernet">  以太网 </a> <rt>  Ethernet </rt></ruby> 技术而闻名，这项技术允许高速数据通过同轴电缆进行传输。以太网已经成为全球标准的有线局域网，并在企业和家庭中得到广泛应用。值得一提的是，以太网在诞生五十年后的今年，它被授予了 <ruby> <a href="https://ieeemilestones.ethw.org/Milestone-Proposal:Ethernet_Local_Area_Network_(LAN),_1973-1985">  IEEE 里程碑 </a> <rt>  IEEE Milestone </rt></ruby> 称号。


### 连接 PARC 的 Alto 计算机


以太网的开发始于 1973 年。当时，[Charles P. Thacker](https://amturing.acm.org/award_winners/thacker_1336106.cfm) 在设计阿尔托计算机，他设想了一个网络，能让阿尔托计算机与激光打印机、PARC 的 [ARPANET](https://ethw.org/ARPANET) 网关，以及其他阿尔托计算机进行通信。于是，PARC 的研究员、IEEE 会士 [Robert M. Metcalfe](https://ethw.org/Robert_M._Metcalfe) 接下了这项技术挑战。不久后，计算机科学家 [David Boggs](https://ethw.org/David_Boggs) 也加入到了 Metcalfe 的团队中。


对 Metcalfe 和 Boggs 来说，他们有两个目标：一是网络必须足够快，以支持他们的激光打印机；二是网络必须能在同一栋建筑内连接数百台计算机。


以太网的设计灵感来源于 [夏威夷大学](https://www.hawaii.edu/) 的 <ruby> <a href="https://spectrum.ieee.org/alohanet-introduced-random-access-protocols-to-the-computing-world">  加入链路在线夏威夷地区网络 </a> <rt>  Additive Links On-line Hawaii Area network </rt></ruby>（ALOHAnet），这是一种基于无线电的系统。计算机一旦有信息需要发送，就会立即通过一个共享通道进行传输，这个数据包的前栏会注明接收者的地址。若两个信息包发生冲突，发送的计算机会暂停一段随机的时间间隔后重试。


Metcalfe 在一封现在已 [广为人知的备忘录](https://ieeemilestones.ethw.org/w/images/a/af/Ref1_PARC_Ethernet_Memo_1973.pdf) 中，向同事们提出了他的提案，早期的时候它被称为“<ruby> 阿尔托 Aloha 网络 <rt>  Alto Aloha Network </rt></ruby>”。他提出，使用同轴电缆而不是无线电波可以让数据传输更快，并减少干扰。电缆的使用也意味着，用户可以在不关闭整个系统的情况下，随时加入或退出网络。Metcalfe 在 2004 年接受 <ruby> <a href="https://www.ieee.org/about/history-center/">  IEEE 历史中心 </a> <rt>  IEEE History Center </rt></ruby> 的 [口述历史](https://ethw.org/Oral-History:Robert_Metcalfe) 访谈时如是说。


Metcalfe 说:“有一种名为有线电视 <ruby> 压接器 <rt>  tap </rt></ruby> 的设备，可以在不割断同轴电缆的情况下，接入电缆信号。因此，[Boggs 和我]选择了同轴电缆作为我们的通信手段。在这封备忘录之中，我描述了以太网的运作原理——它是非常分布式的，没有中心控制，只是一个单一的‘<ruby> 以太 <rt>  Ether </rt></ruby>’片段。”


1973 年，Metcalfe 和 Boggs 设计了今日我们所说的以太网的最初版本。它最初的传输速率达到了 2.94 Mbps，“速度足够快，可以供给激光打印机，而且容易通过同轴电缆发送，”Metcalfe 对 IEEE 历史中心说。


一根粗细为 9.5 毫米、质地坚硬的同轴电缆被铺设在 PARC 大楼的走廊中央。这条长达 500 米的电缆上，通过所谓的 “<ruby> 吸血鬼压接 <rt>  Vampire Tap </rt></ruby>”（即 <ruby> N 连接器 <rt>  N connector </rt></ruby>）连接了 100 个收发信节点。这些压接有一个坚硬外壳，它们通过两个类似探针的器件“咬”穿电缆的外绝缘体，接触到了电缆的铜芯。这么一来，在不影响现有连接活跃状态的情况下，就可以增加新的节点。


每个 “吸血鬼压接” 内部都装配了一个 D 型连接器插口，由配对的九个插脚和九个插槽的插头插座组成。这些插座使得阿尔托算机、打印机以及文件服务器能连接到网络上。


为了让这些设备进行交流，Metcalfe 和 Boggs 创建了最早的高速<ruby> 网络接口卡 <rt>  network interface card </rt></ruby>（NIC） —— 这是一块插在计算机主板上的电路板。它包含了现在我们所说的以太网端口。


为了让人们更加清楚地理解，这个系统可以支持任何电脑，研究人员将最初的名字，“<ruby> 阿尔托 Aloha 网络 <rt>  Alto Aloha Network </rt></ruby>”，更改为了 “<ruby> 以太网 <rt>  Ethernet </rt></ruby>”。这个新名字反映了 Thacker 早期的一种观点，他说，同轴电缆其实就是“被困的以太”。PARC 的研究员 [Alan Kay](https://amturing.acm.org/award_winners/kay_3972189.cfm) 曾 [回忆](https://spectrum.ieee.org/xerox-parc) 起这一点。


Metcalfe、Boggs、Thacker 以及 [Butler W. Lampson](https://amturing.acm.org/award_winners/lampson_1142421.cfm) 在 1978 年因他们的发明获得了美国专利。


他们继续完善这项技术，并终于在 1980 年，PARC 推出了速度为 10 Mb/s 的以太网。根据这份 IEEE 里程碑奖项的描述，这一更新是与英特尔和 <ruby> <a href="https://en.wikipedia.org/wiki/Digital_Equipment_Corporation">  数字设备公司 </a> <rt>  Digital Equipment Corp. </rt></ruby>（DEC）的研究员共同进行的，旨在为全行业创造出一种通用的以太网版本。


### 接纳为 IEEE 标准


以太网自 1980 年开始商业化后，其快速地演化成为整个行业的局域网标准。为了向计算机公司提供相关技术的框架，[IEEE 802 局域网标准委员会](https://grouper.ieee.org/groups/802/es-ecsg/) 在 1983 年 6 月将以太网正式定为标准。


目前，[IEEE 802](https://www.ieee802.org/#:~:text=The%20IEEE%20802%20LAN%2FMAN,them%20on%20a%20global%20basis.) 系列已经包含了 67 项已发布的标准，并且还有 49 个项目正在进行中。该委员会和全球各地的标准机构合作，将部分 IEEE 802 标准发布为国际指导准则。


在 PARC 设施外，有一块表彰这项技术的铭牌。其内容如下：



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> 以太网有线局域网起源于 1973 年的施乐帕洛阿尔托研究中心 （PARC），其灵感源自于 ALOHAnet 数据包无线电网络和 ARPANET。施乐、DEC 和英特尔在 1980 年一起发布了一项针对通过同轴电缆的 10 Mbps 以太网的规范，这就成为了 IEEE 802.3-1985 标准。随后该标准进行了增强，提供了更高的速度，支持双绞线、光纤和无线媒介后，以太网在全球的家庭、商业、工业和学术环境中几乎无处不在。
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由 IEEE 历史中心管理并得到 [捐赠者支持](https://www.ieeefoundation.org/donate_history) 的 IEEE 里程碑项目，专门表彰全球各地的杰出技术进步。


[IEEE 圣塔克拉拉谷分部](https://ieeescv.org/) 赞助了这项提名。该捐赠仪式将于 5 月 18 日在 PARC 设施举行。


*（题图：MJ/55dfc9c2-7aaa-447b-9897-8dbb49cdfbcf）*




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via: <https://spectrum.ieee.org/ethernet-ieee-milestone>


作者：[JOANNA GOODRICH](https://spectrum.ieee.org/u/joanna-goodrich) 译者：[ChatGPT](https://linux.cn/lctt/ChatGPT) 校对：[wxy](https://github.com/wxy)


OK
The [Xerox](https://www.xerox.com/en-us) [Palo Alto Research Center](https://spectrum.ieee.org/xerox-parc) in California has spawned many pioneering computer technologies including the [Alto](https://spectrum.ieee.org/xerox-alto)—the first personal computer to use a graphical user interface—and the first laser printer.

The PARC facility also is known for the invention of [Ethernet](https://ethw.org/Ethernet), a networking technology that allows high-speed data transmission over coaxial cables. Ethernet has become the standard wired local area network around the world, and it is widely used in businesses and homes. It was honored this year as an [IEEE Milestone](https://ieeemilestones.ethw.org/Milestone-Proposal:Ethernet_Local_Area_Network_(LAN),_1973-1985), a half century after it was born.

## Connecting PARC’s Alto computers

Ethernet’s development began in 1973, when [Charles P. Thacker](https://amturing.acm.org/award_winners/thacker_1336106.cfm)—who was working on the design of the Alto computer—envisioned a network that would allow Altos to communicate with each other, as well as with laser printers and with PARC’s gateway to the [ARPANET](https://ethw.org/ARPANET). PARC researcher [Robert M. Metcalfe](https://ethw.org/Robert_M._Metcalfe), an IEEE Fellow, took on the challenge of creating the technology. Metcalfe soon was joined by computer scientist [David Boggs](https://ethw.org/David_Boggs).

Metcalfe and Boggs had two criteria: The network had to be fast enough to support their laser printer, and it had to connect hundreds of computers within the same building.

The Ethernet design was inspired by the [Additive Links On-line Hawaii Area network](https://spectrum.ieee.org/alohanet-introduced-random-access-protocols-to-the-computing-world) (ALOHAnet), a radio-based system at the [University of Hawai’i](https://www.hawaii.edu/). Computers transmitted packets, prefaced by the addresses of the recipients, over a shared channel as soon as they had information to send. If two messages collided, the computers that had sent them would wait a random interval and try again.

Metcalfe outlined his proposal, then called the Alto Aloha Network, in a [now-famous memo](https://ieeemilestones.ethw.org/w/images/a/af/Ref1_PARC_Ethernet_Memo_1973.pdf) to his colleagues. Using coaxial cables rather than radio waves would allow faster transmission of data and limit interference. The cables also meant that users could join or exit the network without having to shut off the entire system, Metcalfe said in a 2004 [oral history](https://ethw.org/Oral-History:Robert_Metcalfe) conducted by the [IEEE History Center](https://www.ieee.org/about/history-center/).

“There was something called a cable television tap, which allows one to tap into a coax without cutting it,” Metcalfe said. “Therefore, [Boggs and I] chose coax as our means of communication. In [the] memo, I described the principles of operation—very distributed, no central control, a single piece of ‘ether.’”

Metcalfe and Boggs designed the first version of what is now known as Ethernet in 1973. It sent data at up to 2.94 megabits per second and was “fast enough to feed the laser printer and easy to send through the coax,” Metcalfe told the IEEE History Center.

A 9.5-millimeter thick and stiff coaxial cable was laid in the middle of a hall in the PARC building. The 500-meter cable had 100 transceiver nodes attached to it with N connectors, known as vampire taps. Each of the taps—small boxes with a hard shell—had two probes that “bit” through the cable’s outer insulation to contact its copper core. Thus new nodes could be added while existing connections were live.

Each vampire tap had a D-type connector socket in it, consisting of a plug with nine pins that matched to a socket with nine jacks. The sockets allowed Alto computers, printers, and file servers to attach to the network.

To enable the devices to communicate, Metcalfe and Boggs created the first high-speed network interface card (NIC)—a circuit board that is connected to a computer’s motherboard. It included what is now known as an Ethernet port.

The researchers changed the name from the original Alto Aloha Network to Ethernet to make it clearer that the system could support any computer. It reflected a comment Thacker had made early on, that “coaxial cable is nothing but captive ether,” PARC researcher [Alan Kay](https://amturing.acm.org/award_winners/kay_3972189.cfm) [recalled](https://spectrum.ieee.org/xerox-parc).

Metcalfe, Boggs, Thacker, and [Butler W. Lampson](https://amturing.acm.org/award_winners/lampson_1142421.cfm) were granted a U.S. patent in 1978 for their invention.

They continued to develop the technology and, in 1980, PARC released Ethernet that ran at 10 Mb/s. The update was done in collaboration with researchers at [Intel](https://www.intel.com/content/www/us/en/homepage.html) and the [Digital Equipment Corp.](https://en.wikipedia.org/wiki/Digital_Equipment_Corporation) (DEC) to create a version of Ethernet for broad industry use, according to the Milestone entry.

## Becoming an IEEE standard

Ethernet became commercially available in 1980 and quickly grew into the industry LAN standard. To provide computer companies with a framework for the technology, in June 1983 Ethernet was adopted as a standard by the [IEEE 802 Local Area Network Standards Committee](https://grouper.ieee.org/groups/802/es-ecsg/).

Currently, the [IEEE 802](https://www.ieee802.org/#:~:text=The%20IEEE%20802%20LAN%2FMAN,them%20on%20a%20global%20basis.) family consists of 67 published standards, with 49 projects under development. The committee works with standards agencies worldwide to publish certain IEEE 802 standards as international guidelines.

A plaque recognizing the technology will be displayed outside the PARC facility. It will read:

*Ethernet wired LAN was invented at Xerox Palo Alto Research Center (PARC) in 1973, inspired by the ALOHAnet packet radio network and the ARPANET. In 1980 Xerox, DEC, and Intel published a specification for 10 Mbps Ethernet over coaxial cable that became the IEEE 802.3-1985 Standard. Later augmented for higher speeds, and twisted-pair, optical, and wireless media, Ethernet became ubiquitous in home, commercial, industrial, and academic settings worldwide.*

Administered by the IEEE History Center and [supported by donors](https://www.ieeefoundation.org/donate_history), the Milestone program recognizes outstanding technical developments around the world.

[IEEE Santa Clara Valley Section](https://ieeescv.org/)sponsored the nomination. The dedication ceremony is scheduled for 18 May at the PARC facility.

[The Pioneer Behind Electromagnetism ›](https://spectrum.ieee.org/the-pioneer-behind-electromagnetism)[50 Years Later, We’re Still Living in the Xerox Alto’s World ›](https://spectrum.ieee.org/xerox-alto)[Xerox Parc’s Engineers on How They Invented the Future ›](https://spectrum.ieee.org/xerox-parc)[35 Years Ago, Researchers Used Brain Waves to Control a Robot - IEEE Spectrum ›](https://spectrum.ieee.org/brain-waves-control-a-robot)[How Engineers at Digital Equipment Corp. Saved Ethernet - IEEE Spectrum ›](https://spectrum.ieee.org/how-dec-engineers-saved-ethernet)[50 Years Later, This Apollo-Era Antenna Still Talks to Voyager 2 - IEEE Spectrum ›](https://spectrum.ieee.org/apollo-era-antenna-voyager-2)

[Joanna Goodrich](https://spectrum.ieee.org/u/joanna-goodrich)

[Joanna Goodrich](https://twitter.com/theamarnamove) is the associate editor of *The Institute*, covering the work and accomplishments of IEEE members and IEEE and technology-related events. She has a master's degree in health communications from Rutgers University, in New Brunswick, N.J.