scope:

This service definition is compliant with the UPnP Device Architecture version 1.0. This service-type models physical and link layer properties specific to a Plain Old Telephone System (POTS) modem used for Internet access on an InternetGatewayDevice*. These properties are common across the different instances of WANPPPConnection on the same WANDevice. The service is OPTIONAL (for gateways that support an integrated POTS modem) and is specified in urn:schemas-upnp-org:device:WANConnectionDevice one or more instances of which are specified under the device urn:schemas-upnp-org:device:WANDevice An instance of WANDevice is specified under the root device urn:schemas-upnp-org:device:InternetGatewayDevice the Service State Table (SST) of this service has dependencies on the WANPPPConnection service and must be used in the context of one or more WANPPPConnection instances.