Microsoft eventually replaced the raw ncacn_http implementation with (and later, MAPI over HTTP). They took the same concept but locked it inside an armored truck. Now, the RPC data wasn't just inside HTTP; it was encrypted inside SSL/TLS.
It is formally defined by Microsoft as , first introduced in Windows 2000 and significantly matured in subsequent versions, eventually evolving into RPC over HTTP v2 . ncacn_http
But the core DNA remains. When you open Outlook on your laptop at a coffee shop today and it magically connects to the corporate server without a clunky VPN, you are benefitting from the legacy of ncacn_http . ncacn_http