The Cisco Unified SIP Phone 3911 is now obsolete (past End-of-Life and End-of-Support status).
End-of-Sale Date: 2010-07-23
End-of-Support Date: 2015-07-24
Cisco's End-of-Life Policy
You can view a listing of available Cisco Unified SIP Phone 3900 Series offerings that best meet your specific needs
If you want support information for the Cisco Unified SIP Phone 3911 documentation, it may be available through Cisco.com Search or in the Cisco Community