Washington: A team from the California Institute of Technology in Pasadena, has developed a system called Fast TCP which facilitates the downloading of an entire movie in just five seconds.

An added advantage of Fast TCP is that it can run on the existing internet infrastructure. All traffic on the internet today uses Transmission Control Protocol, which was developed in the 1970s.

This system breaks down large files into small packets of about 1500 bytes, each carrying the address of the sender and the recipient. The sending computer transmits a packet, waits for a signal from the recipient and then sends the next packet. If no receipt comes back, the sender transmits the same packet at half the speed, getting slower each time, until it succeeds. This means that even minor glitches on the line can make a connection very sluggish.

Though Fast TCP uses the same packet sizes as regular TCP, the difference lies in the software and hardware of the sending computer, which continually measures the time it takes for sent packets to arrive, and how long acknowledgements take to come back. This reveals the delays on the line, giving early warnings of likely packet losses. The Fast TCP software uses this to predict the highest data rate the connection can support without losing data.

This improved "Internet 2" infrastructure is currently being developed for scientific data transmission between 200 universities around the world. Caltech is already in talks with Microsoft and Disney about using it for video on demand.

ANI