Abstract：Virtual Circuit Connectivity Verification (VCCV) is an OAM（Operation and Maintenance）mechanism of layer 2 Virtual Private Network，which belongs to a scope of Pseudowire Edge to Edge Emulation（PWE3）technology．VCCV builds a control channel between the endpoints of the pseudowire（PW），and then it transports OAM messages between the two Provider Edge routers through that control channel，so as to achieve the end-to-end fault detection and diagnostics of pseudowire’s forwarding path．
2010, Vol. 1 