Cattigara is thought to be the Roman name for the major port of the Magnus Sinus - the Ptolemic name for the Gulf of Thailand. The Roman Cattigara was Funan era Óc Eo (o'keo / glass canal), which is modern day Thoại Sơn District in Vietnam. There is a man made canal running from Angkor Borei south to Óc Eo that is believed to date from the Funan era.
Thanks. Among the other items of cargo was a great amount of bead stock (carnelian and whatnot, from the subcontinent) that arrived with other cargos but shipped more or less as ballast. The ship would arrive with its main goods, but also shipping bead stock, sell everything (probably piecemeal) then load up with local stuff for the next leg (either back home or further past).