Here is my situation. I will be using the program in Windows platform. It is going to be a 56K external modem, connected by serial or USB cable. I thought I am going to use the RAS functions.

1) Do I have to write the code to connect to the modem or to the serial port?

2) Since the RAS function requires RAS library, which is part of the Windows Platform SDK. Do I have to download it (>900MB) from Microsoft each time I install the program into different computers? Or is there a way I can just install this particular library file into windows?

3) The thing is I don't know where to start. Is there a sample code I can have a look?

Just tell me if you need more information (Sorry, I don't know much about C++ and programming)