This Recommendation aims to specify the signalling requirements of virtualized broadband network gateway (vBNG) for service function chain (SFC). As a background, this Recommendation gives the overview of the vBNG for SFC, with signalling framework between control plane (CP) and Operation Support System (OSS)/ Business Support System (BSS), CP and Authentication, Authorization and Accounting(AAA) systems, CP and user plane (UP). Then this Recommendation depicts the specific requirements and services procedures of the vBNG for SFC.