This document extends the procedures and Connectivity Verification (CV) types already defined for Bidirectional Forwarding Detection (BFD) for Virtual Circuit Connectivity Verification (VCCV) to define Seamless BFD (S-BFD) for VCCV. This document will be extended in future to include definition of procedures for S-BFD over Tunnels. This document extends the CV values defined in RFC5885.