In an MMO backend architecture, the way client connections are handled is really just a tiny implemention detail at the edge of the architecture diagram, only a

In an MMO backend architecture, the way client connections are handled is really just a tiny implemention detail at the edge of the architecture diagram, only affecting a very small part of the overall architecture. Ideally you'd move that stuff out into proxy servers sitting between the clients and the actual game servers with "one connection per client" on the public-network side and "one connection per game server" on the internal-network side. The proxy servers would also deal with validating the incoming traffic (on the message protocol level at least), encryption and of course routing messages between clients and game servers. PS: now that I actually RTFA, the same concept is already mentioned there, it's just called Frontend Server.