Abstract: Network service usage management systems and methods are disclosed. Associations between network services and network service user groups are used to enable usage of network services by members of the network service user groups. The network service user groups are independently and separately manageable, to form respective virtual extranets for instance. Actual usage of the network services may be controlled in accordance with the associations, and possibly also in accordance with respective group policies for the network service user groups. Network service user groups may be self-managed within an administrative domain in which service provider systems supporting the network services are located, or externally managed. Group and service information for externally managed groups may be exchanged between equipment that is within and outside an administrative domain.