Abstract
Virtualizing middleboxes as software for Cloud tenants can eliminate the monolithic processing and static deployment of legacy middleboxes and provide an efficient provisioning for security services. However, inefficient managing of the virtualized security services can reduce the gains of Cloud deployment. We propose a resources-efficient placement of the security functions in the infrastructure of a three-tier Cloud DC by modifying the Best-Fit Decreasing algorithm to solve the problem while satisfying the placement resources and traffic constraints.