Which design factor most impacts call admission control?

• A. Latency and jitter across the network.
• B. Available bandwidth per location/link for voice/video and the CAC method used to enforce it.
• C. Number of end devices in the deployment.
• D. QoS settings on routers alone determining CAC.

Answer: (B)

Call admission control decisions hinge on whether there is enough real, usable bandwidth on each location or link for voice/video and on how the CAC policy enforces that limit. This means you have to know the actual available capacity on every hop a call would traverse and apply a method (such as guard bands, hard or soft CAC, per-link reservations, etc.) to admit or deny new streams. If the per-link bandwidth is already consumed by existing calls or reserved for higher-priority traffic, CAC blocks or degrades new attempts to preserve quality for ongoing calls. Latency and jitter reflect how well the network is meeting its QoS goals, but they’re outcomes rather than the drivers of CAC itself. The number of end devices doesn’t directly determine CAC decisions, and relying only on router QoS settings to decide admission ignores the fundamental resource availability and enforcement policy that CAC uses.