This modem/router works very well with comcast/xfinity, EXCEPT this modem/router will only handle up to 600 mb, according to comcast/xfinity because it is a DOCSIS3.0 modem, if you have 1 gig service you have to get a modem/router that can handle 1 gig according to comcast , that would be a unit that is a DOCSIS3.1 modem.