Joseph Lechleider, a Father of the DSL Internet Technology, Dies at 82

> Mr. Lechleider’s insight about how to increase data speed came when he was 55. He had spent decades studying signal processing, so he was deeply grounded in the field. But Mr. Lechleider, according to Mr. Cioffi, was something of an iconoclast in a large, often bureaucratic organization. “He was not afraid to take a risk and fight for a new idea,” Mr. Cioffi said.

>> ... such meddlesome interference — known as electrical crosstalk — could be drastically reduced if the download speeds were far faster than the upload speeds."

Cool, so DSL is prevented from increasing the upstream traffic by the physics - not a matter of upgrading the 'boxes' at each end of the wire.