Apple has posted a new support document explaining how to configure a firewall or security software to enable iPhone 4 FaceTime video chats over Wi-Fi. The document claims that while FaceTime will “just work” on most Wi-Fi networks, the feature may fail on some networks protected by a firewall. According to the document, port forwarding must be enabled for ports 53, 80, 443, 4080, 5223, and 16393-16472 (UDP) for FaceTime to function correctly on firewall-protected networks. For all other Wi-Fi related issues, Apple refers users to its general Wi-Fi troubleshooting document.
Apple posts guide to running FaceTime behind firewall

Charles Starrett
Charles Starrett was a senior editor at iLounge. He's been covering the iPod, iPhone, and iPad since their inception. He has written numerous articles and reviews, and his work has been featured in multiple publications.