【建造更快互联网】-建造我的世界.docx

【建造更快互联网】 建造我的世界
【建造更快互联网】 建造我的世界

□ 南京大学 陈大为 编译 导读：你在下载音乐、电影或是在线收看节目时，有否为网速奇慢而失望，为不停缓冲而兴味大失？欧美科学家们目前正致力于研究下一代互联网，将会使网速“飙”到前速未有的水平，让我们一起期待海量即时传输互联网新时代的到来！

A conductor in Tokyo moves his baton, and an orchestra in Cleveland starts to play. A few bars later, a violinist in Berlin joins in. To compensate for a slight delay, the musicians play along with an electronic metronome. The performance is broadcasted on high-fidelity speakers and high-definition television. Such a musical experiment would be challenging enough for a television network to pull off; over the Internet, it would be impossible.
That may soon change. Engineers are developing a new type of Internet connection called a dynamic-circuit network that could carry so much data so quickly it might startle even Net surfers in Japan or South Korea. If all goes to plan, the vast data speeds required for such a collaboration may soon be available to all. That might go a long way to solve the problem of how to handle the enormous growth in Internet traffic, which by some estimates is doubling each year.
When a digital photo, YouTube clip or live streaming video is sent over the Internet, the data is first divided into packets, which are routed to the destination and then reassembled. This method tends to break down when large amounts of information are sent along similar pathways at the same time―the different packets are prone to getting hung up on bottlenecks. The result is a Web page that crashes or an online videoconference that sputters and skips. As the Internet starts to stagger under the weight of more and more data, such problems are becoming increasingly common.
Dynamic-circuit network technology would solve the bottleneck problem by opening up a dedicated route from one point to another through which data can be sent without interruption, at speeds thousands of times faster than what’s possible now. Just as quickly, the pathway can be closed and space made available for the next connection. The technology would require some new software and fiber-optic links right up to the PC, but otherwise no change in infrastructure.
The potential difference in data speed is staggering. Whereas a PC can now stream two simultaneous video channels, on a dynamic-circuit network it could send 4,000 channels at once. Downloading a high-definition movie over a cable Internet connection of 4.5 megabytes per second would take about three hours. Over a 10-gigabit-per-second dynamic-circuit network, the same movie would be downloaded in five seconds.
The technology is being developed by Internet 2, a consortium of U.S. universities, companies and scientific and governmental organizations. For now, only a handful of people can use it. It’s being tested on the soon-to-be-operational Large Hadron Collider in Europe, where scientists must share massive amounts of data about the collision of subatomic particles. Astronomers are also using it to share data from radio telescopes. And medical researchers plan to use it to collaborate on long-distance examinations and consultations. Internet 2 hopes to complete testing in May 20XX and roll the technology out shortly after.
The consortium is working on standards and open-source software designed to make the technology freely available to everybody. But some experts aren’t convinced that the Internet needs a new method of sending data. Recent progress in making “packet switching” software more efficient, as well as better optical fiber and faster servers and routers, have convinced them that the old ways work just fine. Even if the new technology isn’t essential, says Internet 2 CEO Doug Van Houweling, “It’s very hard to predict what’s going to happen. Every time we add an important new technical capability to the Internet, really smart people figure out how to do things with it that we never imagined.”

东京的指挥家挥动指挥棒，美国克利夫兰市的管弦乐队开始演奏。当指挥家挥动几下指挥棒后，位于柏林的小提琴家也加入演奏行列。为了补偿传输时间上的延迟，音乐家们随着电子节拍器一齐演奏。这场表演由高保真扬声器和高清晰度电视播放。这样的音乐表演实验对电视网络来说已经足够具有挑战性了，而在因特网上，目前还不可能实现。
这种情况会很快得以改观。工程师们正在研发称为“动态回路网络”的新型因特网连接，这将使网络得以在更短时间内传输更多数据，网速之快甚至会让日本和韩国的[日本、韩国是世界上网速最快的两个国家――译者注]网络冲浪者们都为之震惊。如果一切按照计划，这场音乐演出合作所需要的大量数据快速传输很快将能面向大众。这将在解决因特网日益严峻的交通拥堵问题上进一大步，而有些人估计网络交通量每年增加一倍。
当一幅数码相片，YouTube视频片段或是流媒体视频通过因特网传输时，数据首先会被拆分成数据包，这些数据包各自通过网络传输到达目的地后再被重组起来。而当大量信息同一时间通过同一条通道传输时，这种传输方式就会被打破，不同的数据包被网络瓶颈阻挡住了。结果是网页无法打开或视频会议的传输断断续续或跳帧。在因特网因为越来越多的数据而变得网速蹒跚时，这个问题日益普遍。
动态回路网络技术将会解决网络瓶颈问题。通过建立两点之间的专门通道，数据将得以无阻挡传输，速度将比现在的最快网速还要快几千倍。传输通道会在一条数据传输结束后迅速关闭，从而释放空间实施下一次连接。这项技术只需要一些新软件和连接光纤的个人电脑，而并不需改变网络基础设施。
数据传输速度的潜在差距将是惊人的。目前一台个人电脑可以同时处理两条视频频道，而在动态回路网络上将可以同时发送4 000条频道。用4.5MB每秒的宽带下载高清晰度电影需要大约3个小时，用10GB每秒的动态回路网络下载同样的电影则只需5秒钟。
这项技术正由二代互联网研发中，二代互联网是美国大学、公司、科研和政府机构所建立的一个联盟。现在还只有少数人能使用这种网络。二代互联网将在欧洲即将投入操作的大型强子对撞机项目上使用，这个项目的科学家们需要分享关于次原子粒子碰撞的大量数据。天文学家也将用它来分享射电望远镜的数据。医学研究者则将用它来合作进行远程检查和远程会诊。二代互联网有望在20XX年5月完成测试后很快投入使用。
该联盟目前正在制定标准和公开源程序软件，使得这项技术可以为每个人获得。但是一些专家不认为因特网需要新型数据传输方式。最近在使“数据包转换”软件更有效率方面取得的进展，以及更好光纤、更快服务器和路由器，使他们确信老方法照样管用。既使这项新技术并不必要，二代互联网公司CEO道格・范・豪韦林说，“很难预测会发生什么。每次我们给因特网增加一项重要新技术潜力时，那些非常聪明的人总能想得出一些让我们难以想象的应用方法，而这总会超乎我们的想象。”
（责编：张楚武）

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