Tele-Communication (Telecom) Terms Glossary and Dictionary
CAC: Connection (or Call) Admission Control
Connection Admission Control (CAC), also known as Call Admission Control, refers to the set of actions taken by the network during the call set-up phase (or during call re-negotiation phase) in order to determine whether a connection request can be accepted or should be rejected. In the voice over IP communications, the CACs prevent an IP network from becoming clogged with traffic to the point of being unusable. When a network's capacity is consumed, admissions control mechanisms prevent new traffic from being added to the network. When calls traverse the WAN, admissions control assumes paramount importance. Within the LAN in which bandwidth is not a problem, CAC is less critical. CAC could also be a set of actions taken by each ATM switch during connection setup to determine whether a connection's requested QoS will violate the QoS guarantees for established connections. CAC also is used when routing a connection request through an ATM network.