We use active and passive traffic measurements to identify the issues involved in the deployment of a voice service over a tier-1 IP backbone network. Our findings indicate that no specific handling of voice packets (i.e. QoS differentiation) is needed in the current backbone but new protocols and mechanisms need to be introduced to provide a better protection against link failures. We discover that link failures may be followed by long periods of routing instability, during which packets can be dropped because forwarded along invalid paths. We also identify the need for a new family of quality of service mechanisms based on fast protection of traffic and high availability of the service rather than performance in terms of delay and loss.
Boutremans et al. used active and passive measurements to study the impact of network congestion, link failures, and IS-IS routing instability on voice over IP service on a tier-1 backbone network REF .
Impact of link failures on VoIP performance
NOSSDAV '02
Computer Science