Yeah, CORBA / RMI which microservices eschewed for HTTP. I had a joke years ago that the reason HTTP services became so popular was simply because those ports

Yeah, CORBA / RMI which microservices eschewed for HTTP. I had a joke years ago that the reason HTTP services became so popular was simply because those ports were the only ones open in the firewall, so people used those rather than having to get new ports approved by some convoluted security review.