Received the unrequested new modem. Connected as per instruction.
Old modem had no ethernet wire connection. New modem did. Only computer is a MacBook Pro. Could only connect with internet by connecting ethernet wire from laptop to new modem.
Could not connect with internet if ethernet wire not connected. Laptop then could not be moved beyond length of ethernet wire and connect with internet. Comcast office could not help, phone contact through service number unable to help as it had no serial number for new modem. Forced to buy ethernet connection box from Mac ($100+) to use laptop other than at desk.
Speed of new modem thus connected no better.
Why change modem for additional expense and no better service?
Product or Service Mentioned: Comcast Internet Service.