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 single physical connection of a Digital Subscriber Line (DSL) modem used for Internet access on an InternetGatewayDevice*. These properties are common across the different instances of WANPPPConnection and WANIPConnection services of the same WANConnectionDevice. The service is OPTIONAL for supporting DSL WAN interfaces. The use of this service is relevant only for DSL WAN interfaces of an InternetGatewayDevice. It is specified in: urn:schemas-upnp-org:device:WANConnectionDevice in urn:schemas-upnp-org:device:WANDevice, one or more instances of which are specified under the root device urn:schemas-upnp-org:device:InternetGatewayDevice NOTE: A WANDevice also provides a WANCommonInterfaceConfig service that encapsulates Internet access properties common across all WANConnectionDevice of the same WAN interface WANDevice.