Hi there,
There is a list of reserved portnumbers at:
http://www.iana.org/assignments/port-numbers
and if you search this document for NATI you'll find port 3015 (Datasocket), 3363 (VI Server) and 2343 (logos?) is reserved by National Instruments.
Hope this will help,
Best regards,
Mattias Ericsson, Endevo Sweden