This talk presents, OverQoS, an overlay-based QoS architecture to
provide a better than best-effort communication service for the
Internet. OverQoS can empower third-party providers to offer enhanced
network services to their customers using an overlay network. The key
building block of our architecture is the controlled loss virtual link
(CLVL) abstraction.  The CLVL abstraction provides a statistical bound
on the loss-rate experienced by the overlay traffic between two
overlay nodes, regardless of the nature of the cross-traffic sharing
the corresponding path. The CLVL abstraction enables OverQoS to
provide different types of QoS service models including certain forms
of statistical bandwidth and loss guarantees.  We present an algorithm
for building CLVLs using a combination of forward error correction
(FEC) and automatic repeat request (ARQ).