評論
打印
And we again, we were captivated. How could anybody do this?
我們很好奇，怎么可能做到呢？
And we thought it must be a hoax.
多半是吹牛
And we started looking through libraries, looking for the secret tones that would allow you to do this.
我們開始泡圖書館，尋找打免費電話的秘密
And it turned out that we were at Stanford Linear Accelerate Center one night,
一天晚上我們?nèi)チ怂固垢＞€性加速中心
and way in vaults of their technical library, way down at the last bookshelf in the corner bottom rack.We found an AT&T Technical Journal that laid out the whole thing.
在科技圖書館角落的最后一排書架上，我們找到一份AT&T技術(shù)手冊，揭開了所有的秘密
And that's another moment I'll never forget.
我永遠忘不了那一刻
We saw this journal and we thought "My God! It's all real."
我們看著這份手冊，心想老天這一切都是真的
And so we set out to build a device to make these tones.
于是我們著手制作能夠發(fā)出這種音頻的裝置
And the way it work was, you know when you make long distance call you used to hear "dududududu" right in the background.
它的原理是這樣的，我們打長途電話時會聽到嘟嘟的聲音
They were tones that sound like the touch tone you make on your phone, but with different frequencies so you can make them.
聽起來像撥電話的按鍵音，頻率不同，但可以模擬
It turned out that was the signal from one telephone computer to another,
實際上那是從一臺計算機傳到另一臺計算機的信號
controlling the computers in the network.
它可以控制交換機的工作
And AT&T made a fatal flaw when they designed an original telephone network, digital telephone network, was they put the signal in from computer to computer in the same band as your voice,
AT&T公司設計的數(shù)字電話網(wǎng)絡有嚴重漏洞，他們使用與聲音相同的頻段來發(fā)送控制信號
which meant if you could make those same signals, you could put it right into the handset.
也就是說只要你模擬出相同的音頻信號，通過聽筒發(fā)送出去
And literally, the entire AT&T international phone network would think that you were an AT&T computer.
整個AT&T的國際電話網(wǎng)就會把你當成一臺AT&T計算機
So after three weeks we finally built a box like this, it worked.
三周后我們做出了這樣的一個裝置，真的管用
