MagiNet
The MagiNet is an artificial network of mixed magic and technology including telepathic links, teleportation anchors, aethernet cables as well as radio and wireless networks. Built as a cooperative network of various nations around Eidyn, Valorum, Khyorgan and Swen, it allows for instantaneous communication across all of Erudite. The first experiments were conducted in the 950s ADW though it really gained traction almost exactly 1,000 years after the Demon Wars, the start of Erudite's Cyber Era.
One of the original proposed ideas for the MagiNet was using a series of orbital satellites, but due to the sheer size of Erudite and the limited range, this proved to be unreliable. Instead, many of the physical cables that connect Erudite's communication centers go through Subterra, not only due to the shorter distance but also avoiding threats of sea monsters were the cables to be put into the ocean instead. Naturally, the exact locations of these cables must be considered carefully as Deep Ekati is known to corrupt the signals.