The Cisco TelePresence MCU MSE 8420 is now obsolete (past End-of-Life and End-of-Support status).
End-of-Sale Date: 2013-09-27
End-of-Support Date: 2018-09-28
Cisco's End-of-Life Policy
You can view a listing of available Conferencing offerings that best meet your specific needs
If you want support information for the Cisco TelePresence MCU MSE 8420 documentation, it may be available through Cisco.com Search or in the Cisco Community