What is the purpose of call admission control in a Cisco Collaboration deployment?

• A. To enforce bandwidth limits per location/link and control call admission.
• B. To set QoS markings on packets only.
• C. To encrypt signaling traffic between devices.
• D. To route calls to the nearest gateway only.

Answer: (A)

Call admission control focuses on ensuring voice traffic doesn’t push a network beyond its available capacity. It does this by enforcing bandwidth limits for each location or link and deciding whether a new call can be admitted given the current use and the bandwidth that the call would require. In a Cisco Collaboration deployment, CAC checks the available bandwidth on the path a call would take (including codecs and media streams) and will block or delay a call if admitting it would cause congestion or degrade existing calls. This helps maintain predictable voice quality by preventing oversubscription on WAN links or trunks.

Other functions like marking QoS on packets, encrypting signaling, or routing to a gateway are separate tasks. CAC is specifically about resource-based admission to keep the network from becoming overloaded as calls are established.