A survey of VNF forwarding graph embedding in B5G/6G networks

With the development of heterogeneous network structure, dynamic user requests as well complex service types and applications scenarios, current networks may not accommodate increasingly stringent requirements. As a result, research beyond fifth generation (B5G) or sixth (6G) has been put on agenda. In B5G/6G networks, achieving automatic, flexible, cost-effective orchestration management resources is significant but challenging issue. Network function virtualization (NFV), promising paradigm to address this issue, received considerable attention from both industry academia. NFV leverages technology decouple functions dedicated hardware appliances software middleboxes called virtual (VNFs) that run commodity servers. The demand for becomes request running set VNFs deployed substrate network. requested orchestrated in form VNF-forwarding graph (VNF-FG). problem embedding VNF-FG into known (VNF-FGE). efficiency cost are highly dependent optimization VNF-FGE. This paper mainly presents survey solving VNF-FGE problem. To end, we present general formulation several objectives meanwhile, summarize its different application scenarios four perspectives divide approaches main categories based methods. challenges potential future directions due appearance also discussed.