Call Admission Control (CAC) is a fundamental technology in voice communication networks, both traditional and IP-based. This system is responsible for inspecting and controlling all incoming and outgoing voice network activities through a voice firewall, based on user-defined policies.
How CAC Works
CAC functions as a quality control and call traffic management mechanism within a network. Its primary responsibility is to ensure that available network resources are sufficient to maintain Quality of Service (QoS) during a call. In practice, CAC decides whether a new call can be admitted to the network without compromising existing calls or degrading the quality of service.
Key Components of CAC
- Voice Firewall: The voice firewall is a critical element of CAC. It examines all incoming and outgoing call requests and compares them against user-defined policies. If a call does not meet these criteria, it is rejected.
- User-Defined Policies: Policies are rules set by network administrators that determine how calls should be handled. These rules can be based on various parameters, such as available bandwidth, call type (internal, external, emergency), time of day, and call priority.
- Quality of Service (QoS): QoS is a crucial aspect that CAC must guarantee. This includes parameters such as latency, packet loss, jitter, and bandwidth. CAC ensures that every admitted call meets the pre-established QoS levels.
Benefits of CAC
- Improved QoS: With CAC, the network can maintain high standards of service quality, ensuring that voice calls are clear and uninterrupted.
- Efficient Resource Management: CAC helps manage network resources efficiently, avoiding overloads that can cause service degradation.
- Call Prioritization: In critical situations, such as emergency calls, CAC can prioritize certain types of calls, ensuring they receive the necessary bandwidth.
Conclusions
Call Admission Control is an essential technology for any modern voice network, ensuring that calls are handled effectively and that the quality of service remains high. Through the inspection and control of calls based on user-defined policies, CAC ensures smooth and reliable communication, overall improving the user experience and network efficiency.