Yeah, but both parties can leverage the existing connection without resorting to a message-based protocol, can't they? They could just assume they're now sendin

Yeah, but both parties can leverage the existing connection without resorting to a message-based protocol, can't they? They could just assume they're now sending and receiving bytes after the upgrade. What I meant when I said "utilizing the legacy TCP sever" was creating some plugin that is attached to the server, effectively acting as a lightweight HTTP server that just does the upgrade process (within the same connection). In this way the remaining communication doesn't have to involve message encapsulation/decapsulation each time a message is transferred.