Port 27 question

[chalten () VELOCOM COM AR (Nuņez-Ochoa)]

 Hi all,
         I was port-scanning (netcat) one of our WinNT mail servers and port
27/TCP was open.
 It supose to be reserved for something called NSW User System. It is a
WinNT
 machine, but i search MS info and found nothing about this port. Any
 ideas/suggestions/knowledge what it could be?

 Thanks in advance, Laura