http://support.apple.com/kb/TS1275
Open the proper ports and allow access to Apple servers
During the update and restore process, iTunes needs to contact Apple. Ensure that your computer has the following ports open and can access these servers:
* port 80
* port 443
* phobos.apple.com, albert.apple.com, gs.apple.com
If you experience "Error 9807", you must open access to the following VeriSign servers:
* evintl-ocsp.verisign.com
* evsecure-ocsp.verisign.com

