Leveraging Optics for Network Function Virtualization in Hybrid Data Centers

Network Function Virtualization (NFV) has emerged as a hot topic for both industry and academia. NFV offers a radically new way to design and operate networks, by abstracting physical network functions (PNFs) to virtual NFs (VNFs). This disruptive innovation opens up a wide area of research, as well as introduces new challenges and opportunities - particularly in provisioning VNF forwarding graphs (or network service chains), and the resulting VNF placement issue. While forwarding graphs are often provisioned in the packet domain for fine-grained control over the respective traffic, we argue that doing so leads to lower efficiency; instead, provisioning forwarding graphs using optical transport proves to be far more efficient in intra-data-center (DC) scenarios. While optical service chaining for NFV has already been proposed, we emphasize the use of optical bus architectures for the same. We present an architecture conducive for intra-DC NFV orchestration that can easily be extended to inter-DC scenarios. We deploy switchless optical bus architectures in both the frontplane and backplane of the DC. Our design particularly relies on readily available optical components, and scales easily. We validate our model using extensive simulations. Our results suggest that use of optical transport to provision VNF forwarding graphs can result in significant performance enhancement over packet-based electrical switch provisioning, in terms of packet drops and latency.