SDN and NFV enabled service function multicast mechanisms over hybrid infrastructure

Software-Defined Networking (SDN) and Network Function Virtualization (NFV) are two new paradigms which can accelerate service provisioning. Specifically, NFV decouples proprietary network functions from the hardware and implements them in the form of software which is referred to as Virtual Network Function (VNF). In this way, NFV offers great flexibility for service composition and provision. SDN decouples network control from data forwarding and provides a centralized orchestrator for managing and guiding the provision process of services. However, in the context of SDN and NFV, most researches focus on provisioning the unicast service, while the multicast service provision problem lacks sufficient research. The NFV-enabled multicast is important, which involves not only constructing the multicast topology, deploying and chaining VNFs, but also steering traffic through required VNFs before reaching destinations. In this paper, we propose three efficient heuristics to solve the static, dynamic and scalable multicast problems in the context of SDN and NFV. In particular, the static multicast means that end users do not join or leave the multicast session until it ends, while the dynamic multicast means that end users can join or leave dynamically. The scalable multicast means that network functions can be added to or removed from the multicast service dynamically. The novel strategy of the three heuristics is decoupling traffic forwarding and function deployment. With the decoupling, NFV-enabled multicast can be implemented in multiple stages, during which we can achieve a certain extent of reliability by selectively deploying multiple function instances of the same type. In addition, such decoupling also enables adding or removing functions for multicast services easily, which means that we can also achieve a certain extent of function scalability. The experiment results are achieved under the hybrid environment and show that the proposed heuristics can effectively address the multicast problem in the context of SDN and NFV.