Earlier quoted context omitted.
Almost 30 years ago, I worked on a corporate campus with several different buildings spread out over about 5 miles. There was a SONET ring linking them. I remember a coworker showing me this add-drop multiplexer thing so he could provision a fractional T1 of bandwidth out of the ring. CSU/DSUs, thick serial cables, cisco 2501 routers... We'd laugh at these speeds today.
To get 10Mbps of Ethernet, they would bond together 7x T1s on the SONET side...
I would've liked to see a setup like that. The companies I worked for didn't get much beyond 2x bonded T1s.