Orange Juniper Nokia Telefonica The document specifies a module that updates existing service (i.e., the Layer 2 Service Model (L2SM) and the Layer 3 Service Model (L3SM)) and network (i.e., the Layer 2 Network Model (L2NM) and the Layer 3 Network Model (L3NM)) Virtual Private Network (VPN) modules with the required information to bind specific VPN services to Attachment Circuits (ACs) that are created using the AC service ("ietf-ac-svc") and network ("ietf-ac-ntw") models.