Yes, it is generally possible to use your own modem or router with AT&T Worldnet, but there are some important considerations to keep in mind. First, the modem or router must be compatible with the type of service you are subscribed to, whether it is DSL or fiber. It is essential to ensure that the device meets the technical specifications required for your specific plan. Additionally, while many third-party devices can function well with AT&T services, some features offered by AT&T may not be available when using a personal device. For example, if your equipment does not support certain advanced features such as IPv6, you might experience limitations. It is advisable to check the current guidelines and compatibility lists available on the AT&T website for the most accurate information regarding device compatibility and any specific requirements. This way, you can ensure a seamless internet experience while using your own equipment.