A:Answer The SURFboard SB6190 is a DOCSIS 3.0 cable modem designed for cable internet providers such as Xfinity, Cox, and Spectrum. AT&T provides internet service through Fiber (AT&T Fiber), DSL, and Fixed Wireless, which do not use DOCSIS cable technology. Because of this, the SB6190 won’t work with AT&T service, and you’ll need equipment specifically approved for AT&T.