.sgn indicates the file is digitally signed by Cisco for security and integrity verification.
UNRST (Unrestricted), meaning it does not contain the advanced encryption restricted by some international export laws. Bootable UCSInstall UCOS UNRST 8.6.2.10000-14.sgn.161
If a server's OS partition becomes corrupted, this bootable media can be used to rebuild the node before restoring data from a backup . Bootable UCSInstall UCOS UNRST 8.6.2.10000-14.sgn.161
The file is a bootable installation image for the Cisco Unified Communications Operating System (UCOS) , specifically version 8.6.2. It is primarily used for fresh installations or major upgrades of the Cisco Unified Communications Manager (CUCM) , version 8.6(2a). Core Specifications Version: 8.6.2.10000-14. Bootable UCSInstall UCOS UNRST 8.6.2.10000-14.sgn.161