Multicast-Aware Service Function Tree Embedding

With the technology of Network Function Virtualization (NFV), a multicast service (e.g., real-time multimedia streaming or event monitoring) may be accommodated with a Service Function Chain (SFC). The SFC consists of an ordered set of network functions running on generic physical hardware to provide services from source node to each destination node of the multicast service. In this paper, we define the problem of Multicast-aware Service Function Tree Embedding (M-SFTE), which allows the multicast flows to traverse through network service functions before reaching destination nodes. The M-SFTE maps user's SFC-based multicast requests onto a shared substrate network while considering the constraints of network functionality, computing demand of each virtual network function node, and the bandwidth demand of the request. We propose a novel algorithm, called Minimum Cost Multicast Service Function Tree (MC-MSFT) to jointly optimize the process of constructing SFC-based multicast tree and allocating requested resource to embed the tree onto the physical network. The experimental results show that the MC-MSFT algorithm outperforms the traditional greedy-based algorithms as much as by 35% in terms of the total bandwidth consumption.