I never know that you could buy you own modem . perhaps it be just I not pay attention , but cable company charge far too much to rent a modem to you . for what it would have cost I in a year to rent a modem , I could buy the Motorola surfboard and have it pay for itself in about 10 month . check with you cable company on approve modem . this one be a 3 star recommend modem from Comcast and it have yet to fail I . it be fast , reliable , and easy to set up - so easy that someone without much experience with technology could set it up .