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What is the purpose of CAC (Call Admission Control) in VoIP networks?

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Call Admission Control (CAC) in Voice over Internet Protocol (VoIP) networks serves the crucial purpose of managing and controlling the admission of new calls into the network to ensure efficient and reliable voice communication. The primary objectives of CAC in VoIP networks include:

  1. Bandwidth Management:
    • CAC helps in regulating the usage of available network bandwidth to prevent congestion and maintain optimal call quality. By monitoring the network's capacity, it can make informed decisions about whether to admit or reject new calls based on the available resources.
  2. Quality of Service (QoS) Assurance:
    • VoIP requires a certain level of network quality to deliver clear and reliable voice communication. CAC plays a role in maintaining QoS by avoiding overloading network links and ensuring that sufficient bandwidth is reserved for each active call.
  3. Preventing Network Congestion:
    • VoIP calls are sensitive to network congestion, and excessive traffic can lead to packet loss, latency, and jitter. CAC helps in preventing congestion by controlling the number of simultaneous calls and ensuring that the network's resources are not overwhelmed.
  4. Prioritizing Critical Traffic:
    • CAC can be configured to prioritize critical or high-priority voice traffic over less important data traffic. This ensures that essential voice calls receive the necessary network resources, even during periods of heavy network usage.
  5. Maintaining Call Quality:
    • By preventing the network from becoming overloaded, CAC contributes to maintaining call quality. It avoids scenarios where the available bandwidth is insufficient to support all active calls, leading to dropped calls or degraded voice quality.
  6. Resource Reservation:
    • CAC may involve the reservation of network resources for specific calls, ensuring that the required bandwidth is available for the duration of the call. This reservation mechanism helps in guaranteeing a consistent level of service for active calls.