From Polycom Quick Tip 18298, page 5:
To reset the device settings using multiple key combinations:
For each phone listed below, press and hold the indicated keys in combination.
You must then enter the administrator password before the reset will occur:
• IP 320, 321, 330, 331, 335, 430, and 450: 1, 3, 5, and 7.
• IP 301, 501, 600, 601, and 650: 4, 6, 8, and *.
• IP 4000 and 6000: 6, 8, and *.
• VVX 1500: 4, 6, 8, and *.
Use the key combination when you first power on the phone. If the phone starts "Loading Application" immediately (UCS version 4+), hit cancel then hold down the keys above. It will ask you for the password. The default is "456". If that does not work, you must enter the mac address of the phone (in lower case). There will be a softkey on the display to switch between letters and numbers, and it WILL be hard to tell what is put in because of the "*"s that cover up everthing you enter.
Dan
I blame Avaya.