Check out the section 'Shared Bandwidth' on wiki: https://en.wikipedia.org/wiki/Cable_Internet_access
Check out this comparison: http://www.bestbuy.com/site/tech-tips/compare-cable-dsl/pcmc...
And check out the post by Net_Sharing in this forum: http://www.dslreports.com/forum/r28980221-Speed-Does-cable-b...