Hi
Although Cisco DX650 run android like any other device they are phones designed to work and register with CUCM. I think the TFTP server settings menu will allow you to set up and manage TFTP server information. If neither the primary TFTP server nor the backup TFTP server is listed in the CTL or ITL file on the Cisco Desktop Collaboration Experience device, you must erase the file before you can save changes to the TFTP server 1 (server 2) option. In this case, Cisco Desktop Collaboration Experience deletes the file after you save changes to the TFTP server 1 (server 2) option. A new CTL or ITL file downloads from the new TFTP server 1 (server 2) address.
After Cisco Desktop Collaboration Experience looks for its TFTP server, it gives precedence to manually assigned TFTP servers, regardless of the protocol.
Reference - TFTP Server Settings Menu
Thanks and Regards,
Geevarghese