79afe4ac_nfiguring_the_Blades___DocWiki__Parameter
[Default] none. The T1 span connected to the T1 Smart Blade in slot 1, line A gets sync priority 1, line B gets 2, etc. [Explanation] Specifies the priority of the spans that are set for external timing. The Cisco Unified MeetingPlace system always tries to synchronize from the highest priority span. If the synchronization span goes down, the Cisco Unified MeetingPlace system automatically switches synchronization to the next highest span. If a higher priority span comes up, the Cisco Unified MeetingPlace system automatically synchronizes off of it. [Possible Values] 1-255 (1 is the highest, 255 is the lowest) never [Parameter] 
External sync priority
Cisco Unified MeetingPlace Release 6.1 -- About Configuring the Blades - DocWiki