From a spec standpoint, acoustic modems were building over wires spec'd for bidirectional voice transmissions, i.e. symmetrical. I'm curious about the nuances,

From a spec standpoint, acoustic modems were building over wires spec'd for bidirectional voice transmissions, i.e. symmetrical. I'm curious about the nuances, but it seems like the last mile download/upload imbalance was created by the originating signal mode? Download = First mile internet to ISP could be upgraded to digital, and thus grab some extra throughout by avoiding analog noise handling Upload = First mile user to ISP was inherently analog over phone lines, and so sacrificed throughput for line noise tolerance https://www.edn.com/an-introduction-to-the-v-90-56k-modem/ https://www.edn.com/an-introduction-to-the-v-90-56k-modem/