This will still require port forwarding, but you can choose any port you like essentially. Other than that, there's no easy way to achieve it. There are some alternatives that work in a similar way as TeamViewer (paid and free), but probably would not have VPN feature, or it …

TeamViewer Ports - Which TCP & UDP Ports are Used by This article shows the ports used by TeamViewer, and explains how to block or allow these ports on your computer network. Ports used by TeamViewer. The ports used by TeamViewer are TCP 80, TCP 443 and TCP 5938. How to Allow TeamViewer Ports. You do not need to redirect any ports in order for TeamViewer to work. Teamviewer VPN Feature Explained: How it Works | VPNpro May 26, 2020 A way to use vpn of teamviwer to program with TIA portal The basic big problem is that you must use VPN of teamviewer of course. But the head-ache is that perhaps not all ports are forwarded and so basically this could block everything. Plus there is the TIA Online settings where you should put the VPN virtual adapter.

Nov 29, 2018

In general, TeamViewer will always work if surfing on the Internet is possible. Hence, no firewall configuration is required. As an alternative to port 80 HTTP, port 443 HTTPs is also being checked. In addition, it is also possible to open only port 5938 TCP on the outgoing side.

TeamViewer (팀뷰어) 6 - VPN 연결 : 네이버 블로그

TeamViewer – The Remote Connectivity Software TeamViewer for mobile device support. TeamViewer is the world’s first remote support technology to allow screen sharing on iOS devices from any desktop or mobile device. All Android devices can also be similarly accessed making us the ideal platform for supporting employees in a BYOD or large organization with all kinds of employee devices. TeamViewer: The Remote Desktop Software Your Digital Workforce, Instantly Connected and Remotely Supported Maximize remote workforce productivity with Teamviewer Remote Access and Remote Support. Enable dispersed teams to remote in to the devices they need, the moment they need them – without requiring VPN.