It has a long history and has to do with our topic today, Ethernet.

它有著悠久的歷史，與我們今天的主題 "以太網 "有關。

before we get into today's video

在我們進入今天的視頻之前

if you love our videos,

如果您喜歡我們的視頻

be sure to click the like button below.

請務必點擊下面的 "喜歡 "按鈕。

then, make sure to click subscribe

然後，請務必點擊訂閱

and the little bell to receive notifications of new RealPars videos.

和小鈴鐺，以接收新的 RealPars 視頻通知。

This way you never miss another one!

這樣你就不會再錯過任何一次了！

Ethernet is a communication standard

以太網是一種通信標準

that was developed in the early '80s to network computers and other devices

於 80 年代初開發，用於將計算機和其他設備聯網

in a local environment such as a home or a building.

在當地環境中，如家庭或建築物中。

This local environment is defined as a LAN (Local Area Network)

這種在地環境被定義為局域網（LAN）

and it connects multiple devices so that they can create,

它還能連接多個設備，使它們能夠進行創作、

store and share information with others in the location.

存儲資訊並與位置上的其他人共享資訊。

Ethernet is a wired system

以太網是一種有線系統

that started with using coaxial cable

從使用同軸電纜開始

and has successfully progressed to now using twisted pair copper wiring

併成功發展到現在使用雙絞線銅纜佈線

and fiber optic wiring.

和光纖佈線。

Let's break for a trivia question.

讓我們來回答一個小問題。

Who invented twisted pair wiring?

誰發明了雙絞線？

Alexander Graham Bell invented twisted pair wiring in 1881.

亞歷山大-格雷厄姆-貝爾於 1881 年發明了雙絞線。

In 1983, Ethernet was standardized

1983 年，以太網標準化

into the standard IEEE 802.3

納入標準的 IEEE 802.3

by the Institute of Electrical and Electronic Engineers (IEEE).

由電氣和電子工程師學會 (IEEE) 頒發。

This standard defined the physical layer

該標準定義了物理層

and the MAC (media access control) portion of the data link layer of wired Ethernet.

以及有線以太網數據鏈路層的 MAC（媒體訪問控制）部分。

These two layers are defined as the first two layers

這兩層被定義為前兩層

in the OSI (Open Systems Interconnection) model

在 OSI（開放系統互連）模型中

The “physical” layer consists of the following components:

物理 "層由以下部分組成：

Cabling and Devices.

佈線和設備。

First, let's take a look at Ethernet Cabling;

首先，讓我們來看看以太網布線；

As stated previously, Ethernet cables come as coaxial cable,

如前所述，以太網電纜是同軸電纜、

which is not very common except in older installations,

除了在老式設備中，這種情況並不常見、

twisted pair, and fiber optic.

雙絞線和光纖。

The most common cable is twisted pair cables,

最常見的電纜是雙絞線、

with the latest being Category 6 with speeds up to 1 Gbps

最新的是 6 類，速度高達 1 Gbps

and Cat6a and Cat 7 with speeds up to 10 Gbps.

以及 Cat6a 和 Cat 7，速度可達 10 Gbps。

Category 5 and 5e cables are both still used in many existing applications

5 類和 5e 類電纜在許多現有應用中仍在使用

but handle the lower speeds between 10 Mbps

但可處理 10 Mbps 之間的較低速度

to 100 Mbps but are more susceptible to noise.

但更易受噪聲影響。

The Ethernet twisted pair utilizes RJ-45 eight-pin connectors

以太網雙絞線使用 RJ-45 八針連接器

at either end of the cable that is pinned for transmitting

電纜兩端的針腳用於傳輸數據

and receiving data in either half or full-duplex mode.

以半雙工或全雙工模式接收數據。

Half-duplex transmits data in one direction at a time

半雙工一次向一個方向傳輸數據

while “full-duplex” allows data to be transmitted

而 "全雙工 "允許傳輸數據

in both directions at the same time.

同時向兩個方向移動。

Full-duplex in Ethernet can be achieved by using two pairs of wires

以太網中的全雙工可通過使用兩對導線來實現

to allow data to travel both directions simultaneously.

使數據可以同時雙向傳輸。

Fiber optic cable uses glass or plastic optical fiber

光纖電纜使用玻璃或塑膠光纖

as a conduit for light pulses to transmit data.

作為光脈衝傳輸數據的通道。

It has allowed Ethernet to travel farther distances at higher speeds.

它使以太網能夠以更高的速度傳輸更遠的距離。

Fiber optic cables use several different types of connectors

光纖電纜使用幾種不同類型的連接器

that vary depending on your application needs.

這取決於您的應用需求。

Some of the different types are SFP

其中一些不同類型包括 SFP

(Small Form Pluggable or Small Factor Pluggable)

(小型可插拔系統或小型可插拔系統）

and SC (Subscriber Connector, also known as Square Connector or Standard Connector).

和 SC（用戶連接器，又稱方形連接器或標準連接器）。

In order to use fiber optic in an Ethernet network

為了在以太網網絡中使用光纖

that utilizes twisted pair Ethernet cabling,

使用雙絞線以太網電纜、

you need to use an Ethernet to fiber converter

您需要使用以太網到光纖轉換器

that will allow your network to take advantage of the higher speeds of fiber optic

這將使您的網絡能夠利用光纖的更高速度

and lengthen the distance that the Ethernet network can reach.

並延長以太網網絡的傳輸距離。

How about the Ethernet devices?

以太網設備如何？

Ethernet devices are consist of computers,

以太網設備由計算機組成、

printers or any device which either have an internal NIC

打印機或任何有內置網卡的設備

(Network Interface Card)

(網絡接口卡）

or an external one that is USB or PCI based.

或基於 USB 或 PCI 的外置設備。

“Switches” and “Routers” that act as the director of the network

"作為網絡指揮的 "交換機 "和 "路由器

and connect multiple computers

並連接多臺計算機

or even networks together to enable communication

甚至是網絡一起實現通信

between all the different devices.

所有不同設備之間的連接。

“Gateways” or “Bridges” are used to connect multiple Ethernet networks together

"網關 "或 "網橋 "用於將多個以太網網絡連接在一起

and allow communication across them.

並允許在它們之間進行通信。

Gateways connect two dissimilar networks together

網關將兩個不同的網絡連接在一起

while a bridge connects two similar networks together

橋接器將兩個相似的網絡連接在一起

so that you only see one network.

這樣你就只能看到一個網絡。

Now that we have discussed the basic physical components of Ethernet,

現在我們已經討論了以太網的基本物理組件、

let's move into the second layer of the OSI model, the “data link” layer.

讓我們進入 OSI 模型的第二層，即 "數據鏈路 "層。

The data link layer can be split into two sections;

數據鏈路層可分為兩部分；

the Logical Link Control (LLC)

邏輯鏈路控制（LLC）

and the Media Access Control (MAC).

和媒體訪問控制 (MAC)。

The Logical Link Control establishes paths for data

邏輯鏈路控制為數據建立路徑

on the Ethernet to transmit between devices.

通過以太網在設備間傳輸數據。

The Media Access Control uses hardware addresses

媒體訪問控制使用硬件地址

that are assigned to Network Interface Cards (NIC)

分配給網絡接口卡（NIC）的數據

to identify a specific computer or device

識別特定的計算機或設備

to show the source and destination of data transmissions.

以顯示數據傳輸的來源和目的地。

Ethernet transmits data packets in this data link layer

以太網在此數據鏈路層傳輸數據包

by using an algorithm called CSMA/CD

使用一種稱為 CSMA/CD 的算法

(Carrier Sense Multiple Access with Collision Detection).

(載波偵測多路存取與碰撞檢測）。

CSMA/CD is used as a standard for Ethernet

CSMA/CD 被用作以太網的標準

to reduce data collisions and increase successful data transmission.

以減少數據碰撞，提高數據傳輸的成功率。

The algorithm first checks to see if there is traffic on the network.

算法首先會檢查網絡上是否有流量。

If it does not find any,

如果找不到

it will send out the first bit of information to see if a collision will occur.

它將發送第一個資訊比特，以確定是否會發生碰撞。

If this first bit is successful,

如果第一位成功、

then it will send out the other bits while still testing for collisions.

然後，它將發送其他比特，同時仍在測試碰撞。

If a collision occurs, the algorithm calculates a waiting time

如果發生碰撞，算法會計算等待時間

and then starts the process all over again

然後重新開始

until the full transmission is complete.

直到全部傳輸完成。

When you use the faster Ethernets in full-duplex modes

在全雙工模式下使用速度更快的以太網時

and incorporate switches,

並納入開關、

then you are utilizing a star topology

那麼您使用的是星形拓撲結構

between the switch ports and the devices.

交換機端口和設備之間的連接。

This allows for more direct transmission paths and fewer collisions

這使得傳輸路徑更直接，碰撞更少

as compared to a bus topology where all devices share the same paths.

與總線拓撲相比，所有設備共享相同的路徑。

Ethernet capabilities are quickly changing with new technologies emerging every day.

以太網功能日新月異，新技術層出不窮。

And while we are currently on the brink of successfully moving into speeds higher

雖然我們目前正處於成功邁向更高速度的邊緣

than the current 1 Gbps with 10 Gbps emerging over the last few years,

比目前的 1 Gbps 更快，而 10 Gbps 則是在過去幾年中出現的、

these new Ethernet technologies will be costly.

這些新的以太網技術將耗資巨大。

Also, your possibilities for the information world

此外，您在資訊世界的可能性

can seem endless when you connect this Ethernet local area network

當您連接這個以太網局域網時

to the internet to create a very large WAN (Wide Area Network).

連接到互聯網，形成一個非常大的 WAN（廣域網）。

But that is a story for another day.

但這是後話了。

All in all, Ethernet is popular

總而言之，以太網很受歡迎

because it strikes a good balance between speed,

因為它在速度之間取得了很好的平衡、

cost, and ease of installation.

成本和安裝簡便性。

These benefits, combined with wide acceptance in the computer marketplace

這些優勢，加上在計算機市場上的廣泛認可

and the ability to support virtually all popular network protocols.

並能支持幾乎所有流行的網絡協議。

Want to learn PLC programming in an easy to understand format

希望以通俗易懂的方式學習 PLC 編程

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讓您的職業生涯更上一層樓？

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請訪問 realpars.com