TCP UDP Ports

Hi,

Are the TCP and UDP Ports in RP configurable? Are the only required ports can be used, meaning Open or Closed? I'm trying to port check an RPA using nmap and found several open and closed, but when I tried to nmap a specific port (lets say port 8080), I get a "filtered" status which would mean a packet filtering config. What I'm intending to do is for all required ports to be open and the not required ports closed. No "Filtered" status.

Thanks