Web Application not able to connect to BO when firewall is ON on BO server

My Business Objects Enterprise (R3) is installed on Windows Server 2008 R2. On the server firewall is ON. I have opened port 6400 on the BO server. But, whenever web application from other machine tries to get data from BO, it displays error message. Are there any other ports which need to be opened to have successful connection. Please help.