Evidence for Rome establishing relations/ contact with China

[D B Campbell]

If a Roman of the early Principate (reigns of Augustus through Claudius) wanted to refer to China, specifically, what name would he/she use?

Which begs the question, how on earth would a Roman of the early 1st C even have heard of China?! Educated men like Vergil knew that there was a Land of the Silk People, but they hadn't the foggiest idea where it was.