The superficial answer is, wherever Comcast plugs in to. But I doubt if those organizations want to deal with individuals; that's what Comcast and other ISPs ar

The superficial answer is, wherever Comcast plugs in to. But I doubt if those organizations want to deal with individuals; that's what Comcast and other ISPs are for. Maybe you could go work for Comcast or another ISP, or one of the next level up organizations, and learn about it. https://en.wikipedia.org/wiki/Internet_service_provider https://en.wikipedia.org/wiki/Internet_service_provider https://en.wikipedia.org/wiki/Internet#Infrastructure https://en.wikipedia.org/wiki/Internet#Infrastructure https://en.wikipedia.org/wiki/Outline_of_the_Internet https://en.wikipedia.org/wiki/Outline_of_the_Internet https://en.wikipedia.org/wiki/Internet_access https://en.wikipedia.org/wiki/Internet_access https://en.wikipedia.org/wiki/Internet_backbone https://en.wikipedia.org/wiki/Internet_backbone https://en.wikipedia.org/wiki/Tier_1_network https://en.wikipedia.org/wiki/Tier_1_network