Chapter 2 - 4 (слова "песни" присутствуют) | Текст песни

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There is nearly always more than one route to any destination through a network. If there are ten routes from A to B, it will be quicker to break a message into ten parts and send them all at the same time than to send the whole message along a single path. Packet switching also takes advantage of the fact that the data used by nearly all computers is 'digital'. This means that the original information — sounds or pictures, for example — is translated into a system of numbers. Digital information is very easy to copy. It can easily be broken down into packets and put back together again without losing any data. Vint Cerf is an engineer who has written some of the most important software for today's Internet. He said that digital packets are just like postcards: 'The best way to describe packet-switching technology is to remind you that packets are just like postcards. They've got "to" and "from" addresses on them and they've got a limited amount of content. And, like a postcard, you put them in the post box. If you put two in, you do not know what order they're going to come out in. They might not even come out on the same day. They do not necessarily follow the same paths to get to the destination. The only difference is that an electronic packet goes about a hundred million times faster than a postcard.'
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Now Larry Roberts had plans for the hardware and the software of the ARPAnet. The next question was, who could build it? This was exactly what Larry Roberts asked Wes Clark when Clark gave him the idea for a network of IMPs. 'There's only one person in America who can build your network,' replied Wes Clark. 'Frank Heart.' Larry Roberts knew Frank Heart. They had worked together at Lincoln Laboratory. Heart was an expert in 'real-time systems' - systems that work so quickly that human beings do not notice any delay at all. The ARPAnet did not need to be so fast. But to make packet switching work, lots of very complicated problems of timing would have to be solved. Frank Heart's skills seemed to make him the best man for the job. He was also known as someone who always finished what he started. But Larry Roberts could not simply hire him. Contracts like the ARPAnet were supposed to be offered to many competitors so the government got the best deal. Roberts had to ask for bids from the best companies in the computer and communications industries. In August 1968, he wrote a plan and sent it to 140 technology companies. 'It can't be done,' replied most of them. The biggest names in the computer business at the time were sure that the network could not be built. Both IBM (International Business Machines) and Control Data Corporation said the job was impossible. They said no one could build the network for an acceptable price because the IMPs would have to be enormously expensive mainframe computers. The telephone companies were even more negative. AT&T controlled long-distance phone calls in the USA. 'You'll never make packet switching work,' it said. The telephone companies had never been helpful to computer scientists: 'Please give us good data communications,' the scientists asked. 'We have phone lines everywhere. Use the telephone network,' said the telephone companies. 'But you don't understand,' said the scientists. 'It takes twentyfive seconds to arrange a call, you charge us for at least three minutes, and we only want to send less than a second of data.' 'Go away,' the telephone companies replied. 'We earn tiny sums from data compared to the money that we make from voice traffic.' So the computer scientists went away - and they created the Internet.

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