How does the Cisco Unified CallManager use RSVP?
A. it uses RSVP reservations to request double the bandwidth so calls can flow in both directions
B. it uses the RSVP-configured bandwidth between sites as a method of determining if there is sufficient bandwidth for a call
C. it uses an RSVP-enabled infrastructure and an RSVP agent controlled by Cisco Unified CallManager to request a bandwidth reservation from the network in order to place a call
D. it initiates RSVP reservations from the Cisco Unified CallManager server, which is an active participant in the reservation process
