How to open a port on a router? Complex solution?

Question

Java

Hai people, no matter how funny it is, but from time to time I have been trying to open ports on routers for 5 years. And I score with no luck. At the moment, the tp-link router Model is TL-WR740N.
So a bunch of times I did everything according to the instructions, I checked the port on 2ip.
Yes, I understand that the port will not open until it is needed.
So now I'm doing sockets in c++ and c# (for fun). And yes, with a direct connection to the network (cable in the PC) with ports, everything is fine. But I'm interested in routers.
My task is to write a server in c++, a client in c#, c++ and for android. Everything works great.
Question:
1) Advise a working example where full is described about opening ports on tp-link routers Model TL-WR740N. Tired already.
2) Programs like torrent forward the port themselves. How to google what libraries are available for this or the technology itself. That's interesting, I'd love to read about it.
3) What do you recommend for a good understanding of networks, connections, etc. in general, the mat part. A book, an article, or something else.
Ps Sorry for such a strange question, but I work day and night and I don’t have time to surf the net at work H + if I’m lucky.

Answer 1

1. https://portforward.com/tp-link/tl-wr740n/
www.pcwintech.com/port-forwarding-tp-link-tl-wr740...
forum.tp-linkru.ru/viewtopic.php? t=9
But don't forget that this requires a static IP address of the server, and the best way to do this is to write a static MAC-IP dependency. According to the third link, it is.
2. Google UPnP. Let's take a look here. Using UPnP C++
3. I don't even know myself. Somehow understanding gathered itself from pieces. True, I once established local "networks" via COM and LPT cables. And then in black cut into different games on the Internet. Of course, this did not give me the intricacies of setting up large networks, but I roughly understand how packets go.

Answer 2

Maybe your provider does not give you an external ip?
Here on this photo from top to bottom: https://i.stack.imgur.com/z2E6U.png
- the port to which we will access from the outside
- the port to which the packet will be forwarded on the local server
- the local address of the server
- the protocol (the type of traffic that will be forwarded) - either tcp or udp, or both at once
- enable or disable this port
forwarding Just open a port - this is to open a port so that you can connect to the router on this port.