I buy this product -lrb- Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem -rrb- for use with COMCAST network . very satisfy to I and I recommend this for the Comcast customer and not to rent the modem from Comcast . I recommend you activate the Modem by yourself if you have Comcast Cable -lrb- TV or Phone -rrb- in you home .