Facetime being Blocked Behind Corporate Firewalls

1. I have not been able to connect successfully using Facetime over my corporate WiFi network.
2. We have even tried having both Facetime users connected on the same WiFi AP but still unsuccessful.
3. You will always encounter a "Connecting" message and then, the call will be dropped.
4. Then, I realize, its probably the Port Blocking issues.
5. Here's an article from Apple --> iPhone 4: Using Facetime behind a firewall.