Update: Modem just died after 3 years usage!
DOCSIS 3.0 with 8x speed! Do not buy the SB6121 as only has 4 channels down/up. This one has 8 channels bonded download speed. The SB6183 has 16 channels but costs $200!. I am very happy with this modem. The DOCSIS 2.0 modems can only do one channel at 30 down/ 5 Mbps up and I was getting choking with many active connections with Bit Torrent running. Motorola Arras SurfBoard Extreme!