Connect to remote database

Hello,

I want to connect to a sqlbase database from host A to a server on a network.

This is how i now connect on a local testmachine with php through an odbc connection.

PHP Code:

    $odbc=odbc_connect('dsn','user','pass');
    if (!$odbc)
    {
    exit("Connection Failed: " . $odbc);
    } 


How i can i do this the best way?

I assume i also have to open port 2155tcp on the firewall from the network and also port 2155tcp from host A?

I hope you can help me!

Best regards