The ActionScript 3.0 Reference says the following about flash.net.NetConnection:
The NetConnection class creates a two-way connection between a client and a server. The client can be a Flash Player or AIR application. The server can be a web server, Flash Media Server, an application server running Flash Remoting, or the Adobe Stratus service. Call NetConnection.connect() to establish the connection.
Does this mean I make a regular HTTP connection to any web server using an NetConnection object? I am a little confused about this as further down the section on the connect() method says connect(): Creates a two-way connection to an application on Flash Media Server or to Flash Remoting, or creates a two-way network endpoint for RTMFP peer-to-peer group communication....Pass an "http" URL to connect to an application server running Flash Remoting.. So, the application server has to have Flash Remoting?
Yes, if I recall good, you’ll need to have an AMF RPC server on the server side.
You can look at AMF PHP, which is an opensource solution for AMF RPC call.
Good luck.