Playing rtmp streams from VLC isn't stable yet. Using the piping method from
here will work, if rtmpdump does.
The server expects the invoking of the method 'gaolVanus' before 'play'. I don't think, that rtmpdump can do this without modification. (Maybe someone who knows better can give a little remark.)
I was able to stream it with my (private) rtmp-lib, so there's hope for you. But I won't modify rtmpdump.