I have set up a multi-user project with some clients on the same local network. This project is working properly.
Is it possible for a client to access and edit this project from outside the local network?
When I try to insert this project on this remote client I use the public IP address of my server (which I have set up to host the project Database) (X.X.X.X) and receive this error:

   Could not reach this computer 'X.X.X.X'!
   Queries to the database server on the computer 'X.X.X.X' are not possible! Possible reason: missing authorization 

When I try to include a port number (X.X.X.X:1433) I receive the same error.

I am able to ping 'X.X.X.X:1433' from the remote client.

What could be the problem?