On sensitive and weighted routing and placement schemes for network function virtualization

Virtualization is a fast-growing technology that is being widely adopted to help improve network and datacenter resource manageability and usage optimization. However, given increasing deployments, new challenges are starting to arise, e.g., such as management complexity. Hence in order to deliver a higher degree of service provisioning flexibility, two key technologies have attracted attention, namely network function virtualization (NFV) and software defined networking (SDN). The former enables the implementation of network functions (NFs) via top-of-the-shelf commodity servers in datacenters. The latter decouples the data and control planes, centralizing flow rules definitions in a controller system to facilitate management and routing. Although recent NFV studies have focused on minimizing resource usage to satisfy a set of requested NFs, they do not consider scenarios with limited resources. Hence this paper presents an optimization-based solution for the joint routing and placement of virtual NFs. In particular, the scheme tries to maximize the number of satisfied requests as well as well minimize routing and deployment costs. The model also introduces weighting factors to allow operators to select cost preferences. However findings indicate that the proposed optimization solution can only be solved for smaller networks. Hence a more scalable greedy heuristic scheme is also developed.