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B. Mayayo:
"Call Admission Control for IP Networks";
Supervisor: B. Statovci-Halimi; Institut für Breitbandkommunikation, 2004.

With the rapid evolution of communication networks and the transformation of the Internet into a commercial infrastructure, demands for service quality have developed. Moreover, the interconnection of earlier isolated networks has formed the needs for multiservice networks, where the differentiation of the service quality provided by the network has become a central issue. The increasing competition also produces big pressures upon service/network providers.
This changes in the nature of networking stress on traffic management. In this field, one of the open issues concerning service level agreements between customers and service providers is the call admission control (CAC), which implies a mechanism taken by the network during the establishment of a connection to determine whether the connection request can be accepted or should be rejected.
Many designs for integrated services packet networks offer a bounded delay packet delivery service to support real-time applications. Therefore, traditional approaches to solve CAC problems are based on an a priori traffic specification of the connections, a solution that results in poor bandwidth utilization. The wide range of the new types of traffic flows caused by the applications has triggered the necessity of another approach, called measurement-based admission control (MBAC). This method, instead of guaranteeing an absolute or a numerically enforced probabilistic bound, promises a reliable bound. With the more relaxed bound, an admission control algorithm can operate without requiring a precise characterization of traffic, instead, it can base its admission decision on on-line measurements. Thus, higher network utilization can be achieved at the expense of weakened service commitments.
In the scope of this thesis, after providing an overview of QoS mechanisms and measurement-based admission control algorithms proposed in the literature, an integrated services simulation framework for making simulations with MBAC algorithms is studied and different source models and scenarios are evaluated. An enhancement call adaptive time window algorithm that simplifies the estimation process is also proposed and tested within this framework by means of simulations.

Admission Control, IP entworks