Dependence-Aware Service Function Chain Design and Mapping

The emerging Network Function Virtualization (NFV) technology decouples network functions from the proprietary hardware, which allows the Internet Service Providers (ISPs) to implement network functions as software running on top of a physical (or substrate) node. With NFV, a Service Function Chain (SFC) is defined as an ordered set of network function instances running on specific substrate network nodes to provide services for client users. In this paper, we define the problem of Dependence- Aware Service Function Chain (D_SFC) design and mapping. We study how to efficiently accommodate user's D_SFC requests in the substrate network while considering the constraints of function dependence, computing demand of virtual nodes and bandwidth demand of the D_SFC. We propose a novel heuristic algorithm, called D_SFC design and resource allocation with Adaptive Mapping (D_SFC_AM), which jointly optimizes the processes of designing a D_SFC and allocating resources requested by the chain. D_SFC_AM employs the proposed techniques of dependence sorting and independent grouping that effectively take into account the node dependence and the resource status of the substrate network. Our experimental results show that the proposed algorithm significantly outperforms the scheme based on the traditional topological sorting in which the process of designing a D_SFC and allocating resources requested by the chain is done sequentially.