Comparison of NGN QoS control models - distributed or centralized

The QoS control can be implemented either in the centralized or distributed model. In the centralized model, the call setup signaling and resource control functions are implemented in the control/signaling servers while distributed model implements the same functions in the transport equipment. Selecting the appropriate control model is critical when deploying the real network. This paper identifies the control procedure of both models and provides a performance comparison on both models. Based on our analysis, the performance of distributed model is better when traffic load is high and traffic is uniformly distributed. When the majority of calls are initiated or destined to one edge node, centralized model has better performance.