Cisco Firewall :: 65535 Make Video Conference Call Through Microsoft Office Communicator

my client wants to make videoconference call thorugh Microsoft Office Communicator, this should be operating between host from one site to another one, but we already configured some rules in the firewalls, and making some test I see that the videoconference use dynamic ports (1024 to 65535) and if we let to operate the videoconference we should remove all the rules in the firewall and that's not the point.