When installing the complete SNA package, you will get at least three more services, AFTP, NVAlert and NVRunCmd.
* AFTP is like its TCP/IP counterpart FTP a tool to transfer files over the net. It might be used for anonymous logins as well.
* NVRunCmd is a service that lets someone running the NetView network monitoring tool send ordinary commands over the net that will be executed locally on the Windows NT machine.
Make sure that you have disabled these services if you want to run a more secure setup.