Hello,
Thank you for your reply. The operator at 1st level relayed the request to the technician who replied that no one is allowed to change the router firmware. I asked to speak directly to the tech but she did not let me through and proposed me to contact the paying Amico stuff...
Now I want to send a written request to Swisscom, hoping that I find someone competent.
After searching and reading documentation for hours I understand that UDP 4500 is reserved for tunelling worldwide, I can't understand why Swisscom is not compliant and refuse to give support 😞
I'll try with SSL, hopping that I can manage.
Thanks anyway and have a nice weekend,