Approximating Low Latency Queueing Buffer Latency

Low latency queueing (LLQ) is an internet protocol (IP) router discipline that is being used to ensure that performance-sensitive high priority traffic, such as voice and video, receive their high level of performance, while allowing less performance-sensitive traffic, such as e-mail or best-effort IP, to receive some portion of the bandwidth. In this paper, we develop a simple analytic approximation for the buffer latency (expected buffer delay) for each traffic class using the LLQ system. The approximation is validated via a simulation model.