ASP.Net MVC 5 app talking to TCP Server

Question

I developed an ASP.Net MVC 5 application hosted on Azure. It needs to exchange data with an accounting software that some of my clients use. This accounting software provides a TCP Server that runs somewhere in the LAN of my clients.

To communicate, I need the IP and the Port of the TCP Server but the TCPServer always gives the local IP so here are my questions:

1) is it possible for a web app like mine establish a communication with a TCPServer hosted at my clients office (and probably runs behind firewalls)

2) If I manage to find the real IP where the TCP Server lives, can this IP changes?

Basically, I am trying to find a elegant and easy way for my clients to setup the connection once within our web app to their Accounting Software Server.

Answer 1

This accounting software provides a TCP Server that runs somewhere in the LAN of my clients. To communicate, I need the IP and the Port of the TCP Server but the TCPServer always gives the local IP

1. is it possible for a web app like mine establish a communication with a TCPServer hosted at my clients office (and probably runs behind firewalls)

   From an external network (Azure)? No, not unless you get into networking matters that would allow some external access (VPN, port forwarding, etc.). Alternatively "some API" that would act like same (aka "gateway" instead of some direct access).

   I will defer to Azure experts on Azure VPN Service

2. If I manage to find the real IP where the TCP Server lives, can this IP changes ?

   That's a question that can only be addressed by your client/IT....