The Cisco 2821 Integrated Services Router is now obsolete (past End-of-Life and End-of-Support status).
End-of-Sale Date: 2011-11-01
End-of-Support Date: 2016-11-01
Cisco's End-of-Life Policy
You can view a listing of available Branch Routers offerings that best meet your specific needs
If you want support information for the Cisco 2821 Integrated Services Router documentation, it may be available through Cisco.com Search or in the Cisco Community