Before purchasing, you should research your current cable ISP and find out how many channels they use for downstream. This modem has only 4 channels, the minimum allowed for a DOCSIS 3.0 modem. Comcast/Xfinity, for example, uses 8 channels. Since each channel has a maximum bandwidth, this modem can not handle the very fastest connections that Xfinity is offering, at least in my market. I recently upgraded to 175Mb/s down from Xfinity, but this modem was maxing out around 135 Mb/s. After researching, I found out the information I just shared about DOCSIS channels. I have since purchased the SB6141 model of this modem, that supports 8 channels. Be aware that Xfinity has announced that several of their markets will be upgraded to DOCSIS 3.1 by the end of 2016. If you live in a major metropolitan area, you might consider holding off on purchasing a new modem until those modems become available. Since upload speeds are often much slower on cable modems, I did not mention upstream channels. In the future, that may be another thing the consumer needs to start considering, if we ever see upload speeds breaking into the 100+Mb/s barrier for residential cable users.
More Info on DOCSIS: (...)
| Brand | ARRIS |
|---|---|
| Series | SB6121 |
| Item model number | SB6121 |
| Item Weight | 1.3 pounds |
| Product Dimensions | 2 x 6.4 x 8.7 inches |
| Item Dimensions LxWxH | 2 x 6.4 x 8.7 inches |
| Color | Black |
| Computer Memory Type | DDR3 SDRAM |
| Department | Electronics & Computers |
| Manufacturer | Motorola |
| ASIN | B004XC6GJ0 |
| Is Discontinued By Manufacturer | No |
| Date First Available | June 1, 2011 |
