This is form www.cisco.com
This phone must be on a DHCP-enabled network before you can perform these steps.
Step 1 Unplug the power cable from the phone and then plug it back in.
The phone begins its power up cycle.
Step 2 While the phone is powering up, and before the Applications Menu button flashes on and off, press and hold #.
Continue to hold # until the message LED on the handset flashes on and off in sequence in red.
Step 3 Release # and press 123456789*0#.
You can press a key twice in a row, but if you press the keys out of sequence, the factory reset will not take place.
After you press these keys, the message LED on the handset flashes faster in red and the phone goes through the factory reset process.
Do not power down the phone until it completes the factory reset process and the main screen appears.
思科IP电话连接到网络中，并可以自动获取IP地址！
1、一直按住#号，电话连接POE交换机。
2、当电话话筒上面的灯闪烁时－松开#号
3、紧接着输入123456789*0#
电话重启两次，就可以恢复出厂配置了。
如果想取消此恢复，连接按两个相同的键。