  Large organizations often have users in multiple sites which are connected
over the Internet. Since resources are limited, communication between these
sites needs to be carefully orchestrated for the most benefit to the
organization. We present a Mission-optimized Overlay Network (MON), a hybrid
overlay network architecture for maximizing utility to the organization. We
combine an offline and an online system to solve non-concave utility
maximization problems. The offline tier, the Predictive Flow Optimizer (PFO),
creates plans for routing traffic using a model of network conditions. The
online tier, MONtra, is aware of the precise local network conditions and is
able to react quickly to problems within the network. Either tier alone is
insufficient. The PFO may take too long to react to network changes. MONtra
only has local information and cannot optimize non-concave mission utilities.
However, by combining the two systems, MON is robust and achieves near-optimal
utility under a wide range of network conditions. While best-effort overlay
networks are well studied, our work is the first to design overlays that are
optimized for mission utility.
