Arris Surfboard, Xfinity Comcast Internet and Voice modemModel Number TM822RCompatible with Xfinity Voice Internet Service Download speeds up to 343 Mbps.DOCSIS 3.0 Cable Modem. 2 Year WarrantyEight download and four upload channels.Battery back up capable battery not included2 carrier-grade Voice over IP VoIP LinesIPv4 IPv6 Support1 Gigabit Ethernet Port. Telephone Port2