以太网是近50年前发明的原始网络技术之一。然而，由于可以部署通信协议的简单性及其能够合并现代进步而不会失去向后兼容性的能力，因此以太网继续统治着事实上的计算机网络标准。
以太网本质上是一项协议，该协议允许计算机（从服务器到笔记本电脑）通过使用路由器，开关和集线器等设备来指导流量的有线网络相互通信。以太网也无线协议无缝地工作。
Its ability to work within almost any environment has led to its universal adoption around the world. This is especially true because it allows organizations to use the same Ethernet protocol in their local area network (LAN) and their wide-area network (WAN). That means that it works well in data centers, in private or internal company networks, for internet applications and almost anything in between. It can even support the most complex forms of networking, like virtual private networks (VPNs) and软件定义的网络部署。
以太网在处理带宽密集型应用程序（例如IP应用程序上的视频流或语音）上没有问题。另一方面，它的简单性还使其能够使用非常微小的，相对不老练的设备（例如构成构成的设备）物联网（IoT），无需任何特殊配置。
以太网如何工作？
以太网通过将要发送到或从设备（例如个人计算机）发送到一个不同尺寸的信息框架的信息的信息来工作。这些框架包含标准化信息，例如有助于通过网络路由框架路线的源地址和目标地址。
而且，由于LAN上的计算机通常共享单个连接，因此以太网是围绕CSMA/CD的原理或使用Collision检测的载体 - 固定多访问构建的。基本上，协议确保在发送任何帧之前未使用该行。如今，这与网络初期相比，这一点远不如建立网络，因为设备通常通过开关或节点与网络有自己的私人连接。而且，由于现在使用完整的双工作用以太网，因此发送和接收渠道也完全分开，因此实际上不会在旅途中发生碰撞。
Other than when encountering a collision situation, there is no error correction in Ethernet, so communications need to rely on advanced protocols to ensure that everything is being transmitted perfectly. However, Ethernet still provides the basis for most internet and digital communications, and also integrates easily with most higher-level protocols, so that is almost never an issue these days.
彩色电缆是以太网网络的关键组成部分
You can’t talk about Ethernet without also talking about cables, since Ethernet is designed for wired networking. And as such, simplifying the cables the protocol uses also helped to push the standard into widespread adoption.
这original standard had Ethernet working with coaxial cable, the kind that is used to support cable television. Coaxial cable is robust and capable of carrying a lot of bandwidth over its thick internal copper wire. But there are tradeoffs. Coax is heavy, difficult to work with, not very flexible and also expensive. That is one reason why most home cable TV installations require a special technician to set them up, while home networking usually doesn’t.
Ditching coaxial, Ethernet switched over to the use of the twisted pair cables which still drive wired networking today. Twisted pair cables used with Ethernet are inexpensive to deploy and also quite flexible, meaning that they can be snaked around corners, inside walls, over ceiling tiles or almost anywhere else to connect servers, routers, hubs, devices and endpoints.
而且，大多数生产以太网电缆的公司很久以前就决定放弃标准的灰色方案，而是以彩色的颜色释放它们。除了铺设服务器房间和数据中心外，颜色编码还使技术人员可以视觉上的网络连接分2020欧洲杯预赛组分组以快速故障排除。
扭曲的配对电缆两端的标准插头与有线电话系统使用的相同连接非常相似，这也使将电缆单击到任何支持以太网连接的设备中变得容易。在大多数情况下，只需插入设备并使用这些电缆之一将其连接到网络上，这是立即获得连接所需的唯一步骤。然后，所有数据包和数据的后端路由都由以太网和其他高级协议（如跨越树。
这longtime standard for Ethernet cables is called Category 5, which is commonly referred to as Cat 5. The Cat 5 standard has been in use since 2001. A normal Ethernet cable supports speeds up to 100 Mb/sec. While the primary function of the cables is to support Ethernet networking, they also work with many telephone and video applications.
如今，一条名为5E类别的高级电缆也用于更快的以太网应用。5E类电缆的目标是100MB/秒以太网，但它们的设计也使它们支持更高的速度，例如千兆以太网，同时仍使用相同的端口进行通用连接。
Who invented Ethernet?
原始的以太网标准是由Xerox Parc工程师于1973年创建的罗伯特·梅特卡夫（Robert Metcalfe）andDavid Boggs，，，，and was inspired by a project being conducted at the University of Hawaii, called ALOHAnet. Primitive by today’s standards, it could only achieve 2.94 Mb/sec in raw speed, but it was one of the first times that computers were actually linked into a network.
在大学环境之外，公众直到1980年才能看到以太网，当时Xerox将其提供给所有人。那时还有其他竞争标准，例如令牌戒指，，，，arcnet和别的。但是从那以后离开公司找到3COM的梅特卡夫（Metcalfe）说服了包括数字设备公司（DEC），英特尔（Intel）和Xerox在内的许多主要行业参与者，与3COM合作，将以太网作为统一标准推动。
As part of that agreement, Xerox dropped its trademark of the Ethernet name, allowing any company to use Ethernet with its products. Bandwidth and throughput was also increased to 10 Mb/sec, which was more than enough to handle most networking tasks at the time, with room to spare. All of that helped Ethernet to become the dominant standard worldwide.
以太网的光明（快速）未来
这simplicity of the Ethernet standard as well as its ability to support faster speeds while also remaining backwards compatible has allowed the protocol to grow alongside many technical advancements. Today, almost any computer or computing device can support speeds up to one gigabit per second. Commonly called Gigabit Ethernet, when you compare its raw speed of 1Gb/sec (which is 1,000 Mbit/s) with the original 10 Mbit/s standard that early Ethernet supported, it’s easy to see how far the protocol has come.
千兆以太网可能为家庭网络和大多数办公室提供足够的带宽。以这种速度，即使在同一网络上有多个用户，即使在在线视频游戏等密集的带宽应用程序也可以完美运行。但是以太网可以做更多的事情。
这IEEE Ethernet Working Group几年前的200 GB/SEC和400 GB/SEC以太网的批准规格。主要是数据中心，互联网服2020欧洲杯预赛务提供商（ISP）和专业组织Network Operations Centersthat would be most interested in those kinds of speeds. A few cloud service providers and others say they are working with 400 Gb/sec speeds in some capacity, although full adoption of the standard seems to be hung up on certain elements like new cabling requirements (the current Cat 5 and Cat 5e cables don’t support those speeds), backwards compatibility issues for devices and increased power consumption requirements within data centers.
Technically, the specification for 800 Gb/sec Ethernet also exists, but nobody is currently using it outside of a test environment. And the interesting thing about Ethernet is that because it is such an open protocol, there is no reason to think that even the 800 Gb/sec speeds are anywhere near the theoretical maximum.
实际上，正在进行研究以为每秒1.6 trabyte标准的基础设定基础，该标准可以在2023年完成。这样的速度可能只在高度特定的应用中才有用。例如，公司或政府实体可能很快将其网络数据备份到异地位置。如果他们有500保持数据的数据发送，则该过程可以在14分钟内完成。
看起来像是不必要的速度，而现在，它们可能是。但是，数据量总是在增长，用户和设备的数量也在互联网上。在不久的将来，今天似乎不必要的速度可能很快成为司空见惯，甚至是一项要求。当那天到来时，即使以太网可能已经年满50或60岁，很明显，这将为挑战做好准备。