Quantum Fiber customers get unlimited data with their internet service and the freedom to stream, game, chat, download, and upload without worrying about additional fees. Quantum Fiber may change, cancel, or substitute offers and services, or vary them by service area, at its sole discretion without notice. Let me know. Internet speeds are not guaranteed due to conditions outside of network control, including customer location, devices, equipment, and access through a wired or wireless connection; see centurylink. Additional restrictions may apply. Small Business. Granted, the ISP industry as a whole took a dip in CenturyLink used to reserve unlimited data for its DSL plans, but since unveiling its Fiber Internet brand, the unlimited data cap also extends to the fiber network. Installation and hardware.