Hi Kai and welcome to the board,
The glass itself is press-moulded, as can be seen from the rim and the vertical mould seam visible on the undecorated band towards the rim (right hand side on the picture). To me, it looks like the pattern is simply moulded in as well, though it is hard to tell from the photo. If not moulded, then I'd suspect it was plate-etched, though this should be easy to determine as if it is etched the lines will be in intaglio rather than relief. Given the chunky construction, bubbles and visible shear mark (about half way up), I believe it has some age. It's not a pattern I immediately recognise, but I'd think second half of the nineteenth century give or take.