Scalable and cost-efficient algorithms for VNF chaining and placement problem

This paper focuses on placement and chaining of virtualized network functions (VNFs) in Network Function Virtualization Infrastructures (NFVI) for emerging software networks serving multiple tenants. Tenants can request network services to the NFVI in the form of service function chains (in the IETF SFC sense) or VNF Forwarding Graphs (VNF-FG in the case of ETSI) in support of their applications and business. This paper presents efficient algorithms to provide solutions to this NP-Hard chain placement problem to support NFVI providers. Cost-efficient and improved scalability multi-stage graph and 2-Factor algorithms are presented and shown to find near-optimal solutions in few seconds for large instances.