Modeling the performance of low latency queueing for emergency telecommunications

Event simulation and analytic modeling are used to evaluate the performance of low latency queueing (LLQ), a queueing discipline available in some Internet packet switching routers for integrated services performance assurance. LLQ combines priority queueing with class-based weighted fair queueing (CBWFQ). Priority queueing is used to ensure satisfying tight delay constraints for real-time traffic, whereas CBWFQ is used to ensure acceptable throughput for traffic classes that are less sensitive to delay. Simulations are developed both using a commercial product, OPNET Modeler, and also custom simulators that we developed. Our custom simulators model two different approaches to CBWFQ; and comparisons between the approaches and that of the commercial simulator are conducted. Our computational experiences (central processing unit [CPU] times for model execution and postprocessing) in using the simulators are described. This work is an important first step in the ability to model a proposed enhancement to LLQ which may be beneficial to emergency telecommunications services.