What is Connection Admission Control?
Connection Admission Control (CAC) is a group of actions and permissions in network communication that specifies where the connection is allowed based on network capability. This scheduled group of network actions is initiated during connection establishment or when calls are reconnected. It is based on a simple algorithm that distinguishes between incoming and outgoing network traffic. CAC is also used to decide which traffic to allow or deny from a particular network. CAC is most commonly used in ATM networks. Also known as Call Admission Control.
In relation to communication, the existence of CAC is common, especially in network-oriented connections (CAC does not provide service for connectionless networks). In addition, CAC plays an important role in connection-oriented networks, especially when it comes to congestion control.
The fundamental role of connection admission control in connection-oriented networks is to decide whether there are enough free system resources available before a new connection is established. An end-to-end connection is only established if the availability of free resources is guaranteed.
CAC does the following two things when it connects:
It connects when resources are free and available.
If the connection is rejected in the absence of free / available resources, a notification is sent back to the originator or requester of the call or connection.
The following factors must be taken into account when establishing or requesting a connection:
The type of service needed
Traffic parameters (source traffic parameters are analyzed)
Both directions request their required QoS, which is also taken into account when the connection is set up.