In an effort to meet application needs, network researchers have designed internet quality of service (QoS) architectures intended to deliver end-to-end performance guarantees to applications. Because such services offer guarantees and must elevate and isolate select traffic from competing traffic, we refer to them as "elevated services" (this is in contrast to forms of QoS that differentiate two or more best-effort service classes none of which is strictly elevated over another [3]). Despite two decades of vigorous research and standards activity, elevated services have failed to deploy. We argue that a fundamental reason for this failure is a confusion between QoS as an underlying technology and QoS as a service offering. Neither customers nor Internet service providers need or want hard performance guarantees. Instead, each wants tools to understand and manage risk.
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