  Policy-based network management (PBNM) paradigms provide an effective tool
for end-to-end resource management in converged next generation networks by
enabling unified, adaptive and scalable solutions that integrate and
co-ordinate diverse resource management mechanisms associated with
heterogeneous access technologies. In our project, a PBNM framework for
end-to-end QoS management in converged networks is being developed. The
framework consists of distributed functional entities managed within a
policy-based infrastructure to provide QoS and resource management in converged
networks. Within any QoS control framework, an effective admission control
scheme is essential for maintaining the QoS of flows present in the network.
Measurement based admission control (MBAC) and parameter based admission
control (PBAC) are two commonly used approaches. This paper presents the
implementation and analysis of various measurement-based admission control
schemes developed within a Java-based prototype of our policy-based framework.
The evaluation is made with real traffic flows on a Linux-based experimental
testbed where the current prototype is deployed. Our results show that unlike
with classic MBAC or PBAC only schemes, a hybrid approach that combines both
methods can simultaneously result in improved admission control and network
utilization efficiency.
