Firmware update 7.7.2 is for AirPort Extreme and AirPort Time Capsule base stations with 802.11ac.
This update:
Addresses an issue that prevents a USB hard drive connected to an AirPort Extreme from appearing as an available disk in Time Machine
Resolves an issue that may intermittently cause a loss in WAN connectivity
Resolves an issue that may result in a network loop
All about AirPort Time Capsule, AirPort Extreme, and AirPort Express base station firmware updates
요약 : 연결된 USB 하드 디스크가 Time Machine 디스크로 표시되지 않는 문제와 WAN 연결이 끊어지는 문제 네트워크 루프 문제 등이 해결됩니다.
http://support.apple.com/kb/HT1218
For more information on using AirPort products, go to the Product Support Page at: http://www.apple.com/support/airport/
http://support.apple.com/kb/DL1708?viewlocale=ko_KR&locale=ko_KR