Internal service accessed from the Internet, how to do?

Question

Network administration

Good evening!
Please tell me, what utility can make the internal service (video communication) available from the Internet?
The bottom line is this, there is a videoconferencing server that works on the LAN, its ip is gray. We set the task to make a seminar with internal and external listeners. it is necessary that people from other cities be able to connect to the internal seminar.

We go to the Internet from the LAN through the gateway on Linux. Port forwarding takes a long time to do and needs to be sorted out.

somehow I came across an article about a utility that forwards access to internal resources from the outside, but I can’t find it and remember the utility.

Maybe someone knows and can tell. Really needed

Answer 1

We go to the Internet from the LAN through the gateway on Linux. Port forwarding takes a long time to do and needs to be sorted out.

Since it is "long", it is unlikely that a firewall is configured there (the rules of which would basically have to be understood), and if so, you can try to forward it in one line (you must agree that one line is not very long and not very difficult). Without saving changes. Those. if something goes wrong, just restart Linux and it will be as it was.

sudo iptables -t nat -I PREROUTING ! -s 192.168.1.0/24 -p tcp --dport 8000 -j DNAT --to-destination 192.168.1.234:80

here 192.168.1.0/24 - you need to substitute your local network with a mask,
8000 - the external port that we forward
192.168.1.234 - the server to which we forward
80 - the port on the server.
If you still want to figure it out, then here: https://www.opennet.ru/docs/RUS/iptables/

Answer 2

Port forwarding takes a long time to do and needs to be sorted out.

Understand.
Or do it like white people - proxying through an intermediate node with a white address.