A Simple Analytical Model to Estimate VoIP Signaling Delays in an HFC Access Network

Voice-over-IP (VoIP) services are emerging as a promising business opportunity for Multiple System Operators (MSOs). Signaling delay is one of the most important quality metrics for VoIP services. For VoIP services over networks with HFC-based access, the contention delay experienced by requests associated with signaling packets often dominates the overall signaling delay. In this paper, we present a simple analytical method to characterize this delay. The analytical method combines a closed queueing network model with a saturation model for contention delay characterization. The mean delays obtained using this method compare well with simulation results. The results also yield useful insights into the engineering of upstream channels in HFC-based access networks.