Remote access S7 300 and MP277

Hi, I need to be able to access both PLC and HMI remotely,what options do I have? my coworkers dont think that VPN is an option as they dont think that any of our customers would allow the machine to have a connection to internet.

the connection type is for a machine that we plan to build alot of so it shouldnt be hard for the customer to plug it in.

CPU S7 315
HMI MP277

We usually get vpn access to our customers but if that is problem you can use teleservice and a gsm modem. Siemens has modems but a company called has Helmholz more variants.

The products on that page seems interesting, but i cant seem to find any with an ethernet connection, is there a way to control the HMI on the mpi connection? the access to the hmi must be for smart service and to be able to update the runtime.

NETLink lite, Ethernet Gateway for MPI/PROFIBUS.
Its suposed to support of all common Simatic Engineering Tool. I have never used this product myself so i dont know if it will work in your application.

Swedish supplier that sells a similar product from IBH