Methods and computer-readable media are provided to enable an Internet protocol (IP) data session to be established between a mobile device and a telecommunications network. To establish an IP data session, it may be determined, prior to authenticating the device, whether the device is authorized to communicate via IPv4, IPv6, or both. A mobile device may be capable of communicating via both IPv4 and IPv6, such as a dual-stack device, but the device may only be authorized for either IPv4 or IPv6. A request to establish the IP data session may first be received from a mobile device, and an IP version with which the mobile device is authorized to communicate may then be determined by querying a customer-profile database. This authorization information may be communicated to an authentication component that authenticates the devices, and subsequently, an IP data session is initiated.