no, there aren't, or certainly not in any sense that
unix might have used the term.  that's part of the confusion.
the file server provides a strict tree.  full stop.
there are no links there.  (there aren't even any i-nodes or files distinct from directory entries.)
the (non-persistent) mount table provides a way to
alias, although that's not its only function,
but it really does resemble the unix mount table
more than any form of hard/symbolic/firm/weak link,
except that it can be per-process.