UPnP could have helped with the router bits and dynamic DNS could help with the internal/external bits. https://upnp-portmapper.sourceforge.io https://upnp-port

UPnP could have helped with the router bits and dynamic DNS could help with the internal/external bits. https://upnp-portmapper.sourceforge.io https://upnp-portmapper.sourceforge.io is fun but UPnP isn't enabled everywhere reliably, and explaining how to do that + ensure it's working is probably only going to work for someone who would know what homebrew is. AirDrop is cool in theory but works about 20% of the time for me. In 2017, the best way to send someone a large file is still to upload it somewhere then give them the link to it. https://getdropsha.re https://getdropsha.re and similar stuff makes that easy enough that your non-technical relatives can use it successfully.