AFAIK there isn't a modern word to describe the common architecture that you describe. About a decade ago, the phrase "hub-and-spokes network" was thrown aroun

AFAIK there isn't a modern word to describe the common architecture that you describe. About a decade ago, the phrase "hub-and-spokes network" was thrown around to describe an architecture with a central server that acted as the mediator. The term "p2p" became popular in this context. ( Napster, bittorrent, tox are all "p2p" because they don't connect to single server. Skype is not "p2p" because all packets go through the skype servers.