Hi Francisco,
On my setup, I see port 8308 being used to communicate with the Blitz server I am on. This is the only one I know of, and I do not know if it is TCP/IP, UDP, etc. Are you a member on the Blitz Forum? Tobi, Egon or Richo should be able to answer this, although there may be other members here to know the answer, too.
Hope this helps,
John