How to use PHP on a hosting with a "white" IP to make an http tunnel to connect to a server with a "gray" IP, which is behind NAT'om?

Question

PHP

Situation:
The server with a white IP is the hostinger.ru data center, which seems to be located in Poland, and the server with a gray IP is a Raspberry Pi that I have in a box at home.
Gray IP - by the fact that it is connected to the Internet through the provider's NAT.
Question root:
You need to have access to a server with a "gray" IP for free. Free hosting is limited to php, mysql and htaccess, and tunneling with regular programs will not work.
How it should work:
All requests that the user sends to the hosting are transmitted to the server (which has a gray IP) and the response of this server is transmitted back (through the hosting) to the user (it is necessary to emulate the operation of pptp using php on the hosting).
Question:
How to make an http tunnel using php, mysql and htaccess and are there any ready-made solutions?
If you do not understand the question:
How to emulate PPTP in php and are there php scripts that work like PPTP (or any other tunnel)?
If you have an answer to the question "How to make a request be sent to the hosting and the response returns to the hosting, but all calculations take place on a server that is connected to the hosting data center via the Internet and through a NAT provider and therefore has a "gray" IP address" ?, but there is no answer to this question, then answer it here: How to get http access to a server with a gray IP from the Internet by any means?
All questions on the topic: How to get http access to a server with a gray IP from the Internet by any means? There is a technology of clustering. How to optimize it? How to create a persistent tunneling connection using php? Will NAS timeouts interfere with my tunneling?
How to use PHP on a hosting with a "white" IP to make an http tunnel to connect to a server with a "gray" IP,




Can php receive and immediately process part of a request without waiting for the request to finish receiving?
Can php send information in chunks?
Most recent discussion.

Answer 1

ssh socket proxy, for example. Well, yes, the topology of the network is completely unclear, what kind of "gray" is it - for whom is it gray? Whether in one network with white? Is it possible to tunnel between them / send a request?

Answer 2

ASPROXY