ReadyNAS 102 Remote Access

The port depends on the protocol you want to use - https and ftps being the ones I'd suggest.  If you want to stream media over the internet, then Plex is your best option.  In all these cases you can set the port number.

I don't recommend trying to enable smb or afp over the internet.

Overall, the most secure way to access your NAS remotely is to use a VPN of some kind.  ReadyCloud is built into your NAS.  OpenVPN is built into many routers (including Netgear Nighthawk and Orbi models).  ZeroTier is another VPN you could use, there is a third-party app available for it on the NAS.  For all these choices there are apps available for PCs (Macs and Windows) and mobile devices (Android and iOS).  These are mostly free, though in the case of plex there is a one-time charge for iOS and Android.

Can you give us some more information on how you want to access the NAS remotely?

That is:

• file access for yourself and perhaps family?
• file access for others (not as trusted)?
• remote administration for the NAS?
• media streaming?