Lower than best effort: a design and implementation

Abstract

In recent years, the Internet architecture has been augmented so that Better-than-Best-Effort (BBF) services, in the form of reserved resources for specific flows, can be provided by the network. To date, this has been realized through two different and sequentially developed efforts. The first is known as Integrated Services and focuses on specific bounds on bandwidth and/or delay for specific flows. The Differential Service model was later introduced, which presented a more aggregated and local perspective regarding the forwarding of traffic. A direction that is missing in today's work on service models is a defined schema used to purposely degrade certain traffic to various levels below that of Best Effort. In a sense, a new direction that provides a balancing effect in the deployment of BBE service. This is particularly evident with continual and parallel short transaction flows (like that used for web applications) over low bandwidth links that are not subject to any backoff penalty incurred by congestion because state does not persist. In a more indirect perspective, our model correlates degraded service with the application of usage and security policies — administrative decisions that can operate in tandem or disjointly from conditions of the network. This paper attempts to address these and other issues and presents the design and implementation of such a new degraded service model and queuing mechanism used to support it.