This service definition is compliant with the UPnP Device Architecture version 1.0. This service-type enables a UPnP control point to configure and control PPP connections on the WAN interface of a UPnP compliant InternetGatewayDevice*. Any type of WAN interface (for e.g., DSL or POTS) that can support a PPP connection can use this service. The service is REQUIRED if a PPP connection is used for WAN access, 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 Generally, Internet connections are set up from a WAN interface of the InternetGatewayDevice to Internet Service Providers (ISPs). However, an implementation MAY support PPP connections that are bridged or relayed (as in the case of some DSL modems) through the gateway device. WANDevice is a container for all UPnP services associated with a physical WAN device. It is assumed that clients are connected to InternetGatewayDevice via a LAN (IP-based network). An instance of a WANPPPConnection service is activated (refer to SST below) for each actual Internet Connection instance on a WANConnectionDevice. WANPPPConnection service provides PPP-level connectivity with an ISP for networked clients on the LAN. More than one instance of WANPPPConnection service may be defined on a WANConnectionDevice – representing multiple user accounts using the same link (username / password) to an ISP. Multiple instances of this service will be distinguished based on the ServiceID for each service instance. In accordance with UPnP Architecture version 1.0, the maximum number of WANPPPConnection service instances is static and specified in the InternetGatewayDevice description document. A WANConnectionDevice MAY include a WAN{POTS/DSL/Cable/Ethernet}LinkConfig service that encapsulates Internet access properties pertaining to the physical link of a particular WAN access type. These properties are common to all instances of WANPPPConnection in a WANConnectionDevice. A WANDevice provides a WANCommonlnterfaceConfig service that encapsulates Internet access properties common across all WANConnectionDevice instances.