The Alternet: Lots of them, if you will, independently invented on lots and lots of worlds. (The Empire’s version is the Dataweave, operating on IIP and mesh network principles.) And then there’s the extranet, which is the Internet-of-Internets that links all of these internets together, although in practice everyone refers to all the networks that aren’t their specific local one as “the extranet”.

It supports most of the same functionality and more (say, pervasive augmented reality, mindcasting, and exomemory transfer, to name three examples), although with certain limitations that the Internet generally doesn’t have to worry about, like light-lag [and the associated possibilities of fun with ansibles] and planetary alignments…