Call Admission Control in CUCM [Notes]

CAC in CUCM

Centralized call-processing deployment
- Standard Locations
- RSVP-enabled locations
(AAR does not apply for calls from within a CUCM cluster to another cluster)

Distributed call-processing deployment
An H.323 gatekeeper with CAC can be used in conjunction with H.323 trunks.
H.323 trunks:
- Intercluster trunk (gatekeeper-controlled)
- H.225 trunk (gatekeeper-controlled)

When using SIP, a SIP trunk is implemented also using it with SIP Preconditions, which allows RSVP-based CAC.