it depends on IF your ISP allows incoming connections… many block them on normal accounts and provide them on special paid accounts… (my last ISP required a ‘fixed ip address’ account, for an extra $20/month
you need to open some port on your internet router in your house, and map that port to some port on the pi…
so, for example, map incoming requests to port 9999 to mm port 8080 on the ip address of the pi
(my pi is at 192.168.2.44)
then you need to know/find out your IP address from outside your home… it might be fixed, or it might stay fixed ‘most’ of the time.
there are free services, dns mappers, that will map a name of your choosing to the ip address u assign.
I use dyndns.org
many routers have function built in that will check each time the router gets an address from the ISP and push an update to the mapper for the name u assign…
now OUTSIDE , you connect to (name made up), myMMatHome.dyndns.org:9999
the code calls to get the ip address from the name, and gets your ISP address 99.205.34.128, (number made up) and uses that
to connect to your router, which passes it on to the pi at port 8080…
to get around all this, teamViewer sharing app REGISTERS you with the code on the teamViewer server as sharing system… on the using side, u give the code and it looks up the and sends a message to the sharing app (over the connection started by the sharer) that someone wants to see what is going on…
there is no INBOUND connection, the sharer connects to the user app…
be careful… lots of spammers scan ISP services for machine with open ports and try different known protocols to connect… and there are lots of nasty hack ways to get into different services (vnc…)… to get into your machine…