Explanation/Reference:
Explanation:
Recommendations and Design Considerations for Unified CM Session Management Edition Deployments
* All leaf clusters that support E-L CAC should be enabled for intercluster E-L CAC with SME.
* SME can be used as a centralized bootstrap hub for the E-L CAC intercluster hub replication network. See LBM Hub Replication Network, for more information.
* All trunks to leaf clusters supporting E-L CAC should be SIP trunks placed in the shadow location to enable E-L CAC on the trunk between SME and the leaf clusters supporting E-L CAC.
* For TelePresence video interoperability, see the section on Call Admission Control Design Recommendations for TelePresence Video Interoperability Architectures.
* Connectivity from SME to any trunk or device other than a Unified CM that supports E-L CAC (some examples are third-party PBXs, gateways, Unified CM clusters prior to release 9.0 that do not support E-L CAC, voice messaging ports or trunks to conference bridges, Cisco Video Communications Server, and so forth) should be configured in a location other than a phantom or shadow location. The reason for this is that both phantom and shadow locations are nonterminating locations; that is, they relay information about locations and are effectively that allow for the transmission of location information in versions of Unified CM prior to 9.0, but they are not supported with Unified CM 9.x Enhanced Locations CAC. Shadow locations are special locations that enable trunks between Unified CM clusters that support E-L CAC to accomplish it end-to-end.
* SME can be used as a locations and link management cluster