AT&T Broadband was AT&T's cable operations, which were composed of the assets of TCI and MediaOne, Prime Cable, as well as two Comcast cable systems (Sacramento, California and northern DeKalb County, Georgia) AT&T acquired later in a system swap. Formed in 1999 as AT&T Digital Cable, it was the largest provider of cable television services. Media and online services for AT&T Broadband customers were originally provided by either Road Runner or Excite@Home. In late 2000, AT&T Broadband acquired several Paragon Cable assets in Oregon and Texas during its merger with Time Warner Cable. AT&T spent over $105 billion to form the cable unit, agreed to sell to Comcast initially for $72 billion, but settled at $47.5 billion due to the declining market.

AT&T went through a corporate restructuring process in 2002, which called for AT&T Wireless, AT&T Business, AT&T Consumer, and AT&T Broadband all to become separate companies. Only AT&T Wireless was spun off (although repurchased later by AT&T), and AT&T Broadband was purchased by Comcast in November 2002.^[1]