Comment by Joker_vD

> transport errors vs business errors

Yes, pretty much.

> But the important thing is all errors business or transport eventually need to map to a HTTP status code because that's the protocol you're ultimately speaking.

"But the important thing is, all errors, business or transport, eventually need to map to the set of TCP flags (SYN, ACK, FIN, RST, ...) because that's the protocol you're ultimately speaking". Yeah, they do map, technically speaking: to just an ACK. Because it's a payload, transported agnostically to its higher-level meaning. It's a yet another application of the end-to-end principle.