This excerpt taken from the VRSN 10-K filed Jul 12, 2007.
Billing and Operational Support System (OSS) Services
We offer advanced billing, payment and customer care services to wireless providers that support advance pay, prepaid and post-paid wireless services. Our Billing & OSS services give wireless providers a single point of access for adding billing features, securing payment options, engaging content, and other operational support services. As part of a converged suite of billing and payment services, our Billing & OSS services support operations at each stage of the customer lifecycle, so providers can activate new products and services with network provisioning solutions; mediate diverse networks and platforms; differentiate their offering with content and applications; and support multiple payment models and methods with secure payment processing.