Similar networks exist today. Two very relevant ones are the Amateur Packet Radio networks in the USA and Europe, and the Internet UUCP computer network.
This network has existed (and evolved) for nearly ten years. It consists of precisely the network proposed above, with packetised message transfer and a dynamic addressing scheme. It can (and does) successfully transfer messages from one side of the USA to the other, and even uses short wave bands for trans-atlantic communication. Many of the above ideas were lifted directly from Packet Radio.
This is a computer network, also using packet style communication between telephone dialup links. A huge master map is maintained centrally, and rolled out every month with updated connections, and costs associated with those connections. Software then determines from these maps the most economical way of routing mail and News, an electronic newspaper, to best take advantage of local phone calls, and cheap night-time calling provided by long-distance services.