Short answers, pulled from the story.
Ptolemy drew a map placing the land of Sinae on the northern shore of the Great Gulf which combined what we now call the Gulf of Tonkin and the South China Sea. His chief port for this region was Cattigara which modern scholars suggest was Óc Eo in Vietnam.
A group claiming to be an ambassadorial mission of Romans arrived at Emperor Huan of Han China in 166 AD. They came from Andun possibly Emperor Antoninus Pius or Marcus Aurelius Antoninus and entered China by the frontier of Rinan or Tonkin present-day Vietnam.
The first Roman glassware discovered in China was a blue soda-lime glass bowl dating to the early 1st century BC excavated from a Western Han tomb in Guangzhou. Other finds include a mosaic-glass bowl found near Nanjing dated to 67 AD and a glass bottle with opaque white streaks found in an Eastern Han tomb of Luoyang.
Pliny the Elder lamented that Rome's womankind and the purchase of luxury goods from India Arabia and the Seres cost the empire roughly 100 million sesterces per year. He remarked on the financial drain of coin from the Roman economy to purchase this expensive luxury despite Senate edicts prohibiting men from wearing silk issued in 14 AD.
In 2010 mitochondrial DNA identified that a partial skeleton found in a Roman cemetery from 1st or 2nd century AD in Vagnari Italy had East Asian ancestry on his mother's side. A 2016 analysis of archaeological finds from Southwark London suggests two or three skeletons from a sample of twenty-two dating to 2nd to 4th centuries AD are of Asian ancestry possibly of Chinese descent.