You are the administrator of a Windows XP Professional computer named Pro1.  The computer is connected to the Internet. Pro1 provides Internet access to eight other Windows XP Professional computers that are connected to Pro1. You enable Internet Connection Sharing (ICS) and Windows Firewall on Pro1. You run an application named App1 on Pro1.  App1 communicates with an online training company on the Internet. To display an online seminar, the training company needs to contact the App1 application at port 5800. You want to ensure that the training company can connect to the App1 application. What should you do?（）