Optical Service Chaining for Network Function Virtualization

This article presents an efficient optical service chaining architecture for network function virtualization in data centers. Service chaining (i.e., steering traffic through a sequence of network functions) is one emerging application of software-defined networking. However, existing schemes steer traffic solely in the packet domain, which is well suited for fine-grained (e.g., peruser level) flows carrying a relatively small volume of traffic. This article discusses how packet-based schemes do not yield sufficient efficiency for large/aggregated flows steered through high-capacity core network functions. It introduces an optical steering domain into the operator's data centers for NFV service chaining at a coarse-grained traffic level using wavelength switching. Performance evaluation shows that the optical steering domain can achieve significant power savings compared to using packet technologies as flow rates and the number of vNFs per service chain grow.