Does anyone have any information about VPNplugin (iOS VPN API)?

Question

iOS

Does anyone know anything about the "secret" VPN API for iOS?
It is used, in particular, by the OpenVPN application to create a vpn connection to an openvpn server. The API is clearly official - the application is available in the App store, but there is no documentation anywhere.
The maximum that could be found is a thread on the developer forum, where a certain eskimo1 describes attempts to reach out to Apple on this issue.
Apparently, this is some kind of private API, which is issued privately to some companies. But suddenly someone here has access.
ps Toaster, you collapsed from oak, move it to / tmp ???

Answer 1

https://github.com/Smartype/iOS_VPNPlugIn

Answer 2

The application server, as far as I know, is the common name for the middle link in a three-tier client-server architecture (Client -> Application Server -> Database Server).
1. Client - graphic/interface part.
2. Application server - a program that implements some part (large or small) of logic.
3. Database server - data and transaction management.
Hence the conclusion, Apache httpd + ( php | perl | jetty ) and Apache Tomcat are application servers, as they perform their role as an intermediary between the client and the database server.
Actually, here it is worth paying attention to why the concept of an application server was introduced at all, what tasks it solves, to understand, so to speak, its essence, through its functions =)

Answer 3

tomcat is a web server + servlet container that handles web requests.
application server - a server that includes a servlet container + implements the entire Java EE API stack (JPA, EJB .. full list here )

Answer 4

Possible architectures:
1. web server-> application (this is most ordinary sites)
2. web server-> application server-> application (large web projects)
3. application server -> application (mobile On-Line / REST- services)
Web server - the "entry point" of client web requests (usually from the browser) and their routing depending on the specified conditions: the desired domain, server (IP), proxying and subsequent transfer further.
An application server is a system for managing and distributing application resources.
Application (or web application) - a script or native code that provides a limited set of functionality to the end user, such as a search engine or a gallery.