B1 中級 6570 分類 收藏
開始影片後,點擊或框選字幕可以立即查詢單字
字庫載入中…
回報字幕錯誤
The Internet in the year 2009.
We send e-mails, make calls over the internet
and discuss topics we take an interest in.
Even our banking is going virtual.
But what we take for granted today
was only a vague idea fifty years ago.
In order to understand how we got this far
let's go back to 1957, when everything began.
Before 1957 computers only worked on one task at a time.
This is called batch processing.
Of course, this was quite ineffective.
With computers getting bigger and bigger
they had to be stored in special cooled rooms.
But then the developers couldn't work directly on the computers anymore –
specialists had to be called in to connect them.
Programming at that time meant a lot of manual work
and the indirect connection to the computers led to
a lot of bugs, wasting time and fraying the developers´ nerves.
The year 1957 marked a big change.
A remote connection had to be installed
so the developers could work directly on the computers.
At the same time the idea of time-sharing came up.
This is the first concept in computer technology
to share the processing power of one computer with multiple users.
On October 4th 1957, during the Cold War
the first unmanned satellite, Sputnik 1, was sent into orbit by the Soviet Union.
The fear of a "Missile Gap" emerged.
In order to secure America's lead in technology,
the US founded the "Defense Advanced Research Project Agency" in February 1958.
At that time, knowledge was only transferred by people.
The DARPA planned a large-scale computer network
in order to accelerate knowledge transfer and avoid the doubling up
of already existing research.
This network would become the Arpanet.
Furthermore three other concepts were to be developed,
which are fundamental for the history of the Internet:
The concept of a military network by the RAND Corporation in America.
The commercial network of the National Physical Laboratory in England.
And the scientific network, Cyclades, in France.
The scientific, military and commercial approaches of these concepts
are the foundations for our modern Internet.
Let's begin with the Arpanet, the most familiar of these networks.
Its development began in 1966.
Universities were generally quite cautious about sharing their computers.
Therefore small computers were put on front of the mainframe.
This computer, the Interface Message Processor, took over control of the network actvitities,
while the mainframe was only in charge of the initialization of programs and data files.
At the same time, the IMP also served as interface for the mainframe.
Since only the IMPs were interconnected in a network
this was also called IMP-subnet.
For the first connections between the computers
the Network Working Group developed the Network Control Protocol [Network Control Program].
Later on, the NCP was replaced by the more efficient Transmission Control Protocol.
The specific feature of the TCP is the verification of the file transfer.
Let's take a short detour to England.
Since the NPL network was designed on a commercial basis
a lot of users and file transfer were expected.
In order to avoid congestion of the lines, the sent files were divided into smaller packets
which were put together again at the receiver.
"Packet Switching" was born!
In 1962 American ferret aircrafts discovered middle and long range range missiles in Cuba,
which were able to reach the United States.
This stoked fear of an atomic conflict.
At that time information systems had a centralized network architecture.
To avoid the breakdown during an attack,
a decentralized network architecture had to be developed,
which in case of loss of a node would still be operative.
Communication still used to work through radio waves,
that would have caused problems in case of an atomic attack:
the ionosphere would be affected and the long-wave radio waves wouldn't work anymore.
Therefore they had to use direct waves, which, however, don't have a long range.
A better solution was the model of a distributed network.
Thus long distances could be covered with a minimum of interference.
Another milestone followed with the development of the French network "Cyclades".
Since Cyclades had a far smaller budget than Arpanet and thus also fewer nodes
the focus was layed on the communication with other networks.
In this way the term "inter-net" was born.
Moreover, Cyclades´ concept went further than ARPA's and the NPL's.
During communication between sender and receiver the computers were not to intervene anymore,
but simply serve as a transfer node.
Cyclades´ protocol went through all machines using a physical layer
that was implemented into the hardware,
providing a direct connection with the receiver – an end-to-end structure.
Inspired by the Cyclades network and driven by the incompatibility between the networks,
their connection gained in importance everywhere.
The phone companies developed the X.25 protocol which enabled communication
through their servers – in exchange for monthly basic charge of course.
DARPA's Transmission Control Protocol was to connect the computers through gateways...
and the International Organization for Standardization designed the OSI Reference Model.
The innovation of OSI was the attempt to standardize the network from its ends
and the channel's division into separate layers.
Finally, the TCP assimilated the preferences of the OSI Reference Model
and gave way to the TCP/IP protocol –
a standard which guaranteed compatibility between networks
and finally merged them, creating the Internet.
By February 28, 1990 the ARPANET hardware was removed, but the Internet...
... was up and running.
Subtitles by HackJack (aka StevXtreme)
提示:點選文章或是影片下面的字幕單字,可以直接快速翻譯喔!

載入中…

網路的歷史 (History of the Internet)

6570 分類 收藏
Zenn 發佈於 2013 年 3 月 16 日
看更多推薦影片
  1. 1. 單字查詢

    在字幕上選取單字即可即時查詢單字喔!

  2. 2. 單句重複播放

    可重複聽取一句單句,加強聽力!

  3. 3. 使用快速鍵

    使用影片快速鍵,讓學習更有效率!

  4. 4. 關閉語言字幕

    進階版練習可關閉字幕純聽英文哦!

  5. 5. 內嵌播放器

    可以將英文字幕學習播放器內嵌到部落格等地方喔

  6. 6. 展開播放器

    可隱藏右方全文及字典欄位,觀看影片更舒適!

  1. 英文聽力測驗

    挑戰字幕英文聽力測驗!

  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔