Access to Engine Socket directly?

Current i made master server that communicates with UE4. i made another UDP Socket on my game ( FSocket ) that communicates with my master server. so i got 2 sockets on my game. the engine socket and my own socket.

I managed the custom socket to send some info to my master when the game launches. like, saying user logined.

after the client send me some packets, my master server can send some info anytime. i mean, even client didn’t setup their port. ( port forwarding and firewall thing )

and their client port seems decided randomly, ( like, some client sending it using port 63434 and other is 34443 )

Im looking for a way to allow other user to join other’s server where didn’t setup their network to allow outside connection.

im currently announcing to people who wants to play with others. ’ open your port 7777 to allow other people join to your server ’

but like i said above, if some node knows its outer port ( randoming port like 63434 ) , can communicate without port forwarding.

im not good at networking so don’t know how it works, but i want to do this below.

  • I want to access to engine socket
    directly and send some packets to my
    master server.

  • when master server get the packet,
    save its outer port.

  • When some player wants to join the
    server, master server tell them their
    outer port.

  • client join the server using some
    command. like ( open
    222.222.222.222:63424 )

to do that, i need a way to access to engine socket directly. is it even possible?

thanks for your help