  One of the main goals of 5G networks is to support the technological and
business needs of various industries (the so-called verticals), which wish to
offer to their customers a wide range of services characterized by diverse
performance requirements. In this context, a critical challenge lies in mapping
in an automated manner the requirements of verticals into decisions concerning
the network infrastructure, including VNF placement, resource assignment, and
traffic routing. In this paper, we seek to make such decisions jointly,
accounting for their mutual interaction, and efficiently. To this end, we
formulate a queuing-based model and use it at the network orchestrator to
optimally match the vertical's requirements to the available system resources.
We then propose a fast and efficient solution strategy, called MaxZ, which
allows us to reduce the solution complexity. Our performance evaluation,
carried out accounting for multiple scenarios representative of real-world
services, shows that MaxZ performs substantially better than state-of-the-art
alternatives and consistently close to the optimum.
