Scheduling Service Function Chains with Dependencies in the Cloud

Cloud services are now well established, thanks to some providers' pioneering work that currently offer on-premise the advantage of the predictability, continuity, and quality of service delivered by virtualization technologies. In this context, SDN (Software Defined Networking) aims to provide tenant-controlled management of forwarding and different abstractions of the underlying network infrastructure to the applications. The scheduling and placement of network functions in the cloud is a challenging task. One reason is that it also requires tedious provisioning and configuration steps. Even if we consider in this paper only the placement of network functions and not their configurations, we are faced with the general problem of defining, in an 'optimal' way, the placement of network functions to be executed so that some criteria are preserved. In this paper, we formulate an approach to schedule network functions according to their dependencies.