Admission control is a network Quality of Service (QoS) procedure^[1]. Admission control determines how bandwidth and latency are allocated to streams with various requirements^[2]. Admission control schemes therefore need to be implemented between network edges and core to control the traffic entering the network. [1] In the fields of packet-switched networks and computer networking, the traffic engineering term Quality of Service (QoS) refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the...

An application that wishes to use the network to transport traffic with QoS must first request a connection, which involves informing the network about the characteristics of the traffic and the QOS required by the application. This information in stored in a traffic contract. The network judges whether it has enough resources available to accept the connection, and then either accepts or rejects the connection request. This is known as Admission Control. Admission Control in ATM networks is known as Connection Admission Control (CAC).^[3] In 802.11 networks it is known as Call Admission Control. If a service (or application) wishes to use a broadband network (an ATM network in particular) to transport a particular kind of traffic, it must first inform the network about what kind of traffic is to be transported, and the performance requirements of that traffic [1]. The application presents this... Asynchronous Transfer Mode (ATM) is a cell relay network protocol which encodes data traffic into small fixed-sized (53 byte; 48 bytes of data and 5 bytes of header information) cells instead of variable sized packets (sometimes known as frames) as in packet-switched networks (such as the Internet Protocol... Admission control, in the most primitive sense, is the simple practice of discriminating which traffic is admitted into a network in the first place [1]. Admission control in ATM networks is known as Connection Admission Control (CAC). ... IEEE 802. ...

Admission control is useful in situations where a certain number of connections (phone conversations, for example) may all share a link, while an even greater number of connections causes significant degradation in all connections to the point of making them all useless.such as in Congestive collapse. Congestive collapse (or congestion collapse) is a condition a packet switched computer network can get into when congestion in the network is bad enough that almost no useful communication is happening. ...

See also

• Congestion Avoidance in Broadband Networks
• Teletraffic engineering in broadband networks
• Call Admission Control
• Network Admission Control
• Asynchronous Transfer Mode (ATM)
• Bandwidth Broker
• 802.11

Future telecommunication networks should have the following characteristics: broadband, multi-media, multi-point, multi-rate and economical implementation for a diversity of services (multi-services) [1][2]. The Broadband Integrated Services Digital Network (B-ISDN) provides these characteristics to a network. ... Teletraffic Engineering is a well-understood discipline in the traditional voice network, where traffic patterns are established, growth rates can be predicted, and vast amounts of detailed historical data are available for analysis. ... Call Admission Control prevents oversubscription of VoIP networks, CAC is a concept that applies only to real time media traffic and not to data traffic. ... Network Admission Control Network Admission Control (NAC) refers to restricting access to the network based on identity or security posture. ... Asynchronous Transfer Mode (ATM) is a cell relay network protocol which encodes data traffic into small fixed-sized (53 byte; 48 bytes of data and 5 bytes of header information) cells instead of variable sized packets (sometimes known as frames) as in packet-switched networks (such as the Internet Protocol... RFC 2638 from IETF defines the entity of the Bandwidth Broker in the framework of DIffServ. ... IEEE 802. ...

References

1. ^ Ferguson P., Huston G. (1998). Quality of Service: Delivering QoS on the Internet and in Corporate Networks. John Wiley & Sons, Inc.. ISBN 0-471-24358-2. 
2. ^ Hiroshi Saito (1993). Teletraffic Technologies in ATM Networks. Artech House. ISBN 0-89006-622-1. 
3. ^ Traffic Control in ATM networks. ATM Forum. Retrieved on 2005-03-03.