79afe4ac_nfiguring_the_Blades___DocWiki__Parameter
[Default] external [Explanation] Specifies if the Cisco Unified MeetingPlace Audio Server should get clock timing from the PBX or central office or if timing is generated by Cisco Unified MeetingPlace. All spans should be configured as external. The internal setting is for diagnostic purposes. [Possible Values] internal external (the span is connected to the public network or a trusted system, such as the PBX) [Parameter] 
Timing
Cisco Unified MeetingPlace Release 6.1 -- About Configuring the Blades - DocWiki