Best DOCSIS 3.1 Gigabit Modems for XFINITY/Comcast, Cox and more

Many ISPs have started Gigabit DOCSIS 3.1 roll-outs in many areas and continue to bring gigabit services to new areas every month.


Nation’s largest Cable ISP Xfinity Comcast publishes and updates map for its gigabit DOCSIS 3.1 deployments and upcoming areas. It recently launched gigabit Internet service based on DOCSIS 3.1 throughout Colorado, its Oregon/SW Washington region and the company’s suburban Kansas City, MO, and Olathe, KS, service areas. Since field trials in Philadelphia and Atlanta at the end of 2015, Comcast has deployed DOCSIS 3.1-based gigabit Internet service in several markets, including Detroit, San Francisco, Chicago, Nashville, Atlanta, Miami and many more. For list of cities check roll out map on the Xfinity Gigabit Website

Spectrum (Charter, Time Warner Cable, BrightHouse Network):

Spectrum was lagging in DOCSIS 3.1 gigabit roll-out but now have many cities with DOCSIS 3.1 deployments. for the list of cities check this link published in April 2018.

Cox Communications

Cox has several DOCSIS 3.1 Gigabit trial regions and they seem to be aggressively working towards DOCSIS 3.1 Gigabit service and have been working with Modem manufacturers to enable DOCSIS 3.1 Cable Modems.


Mediacom Communications recently began launching gigabit Internet based on DOCSIS 3.1 within its Illinois service territory. The deployment will begin with 275 small cities and towns, with an additional 70 communities slated launch in the next two months.The operator already has launched gigabit services in more than 800 communities, including southwest Georgia and the rural southern part of Minnesota. In conjunction, the company also is introducing a new 500 Mbps service.


RCN launched DOCSIS 3.1-based gigabit Internet in the Boston metro area in March. The service costs $69.99 per month and requires no contract. RCN also offers gigabit service in Chicago, New York, Washington DC, Philadelphia and Evanston, IL.

Best DOCSIS 3.1 Gigabit Modem (2018)


SB8200 is based off Broadcom 3390 chipset and comes with 2 x Gigabit Ethernet Ports (supports Link-aggregation)


MB8600 is based off Broadcom 3390 Chipset and comes with 4 x Gigabit Ethernet ports (supports Link Aggregation)


CM1000 is based off Broadcom 3390 chipset and comes with single Gigabit Ethernet Port


CM1150V is based off Broadcom 3390 chipset and comes with 4 Gigabit Ethernet Ports and 2 voice ports

Amazon Link
Number of Ethernet Ports 2 4 1 4
Voice/Phone Capability (Comcast Xfinity Only)
ISPs supported Xfinity/Comcast/Cox and others Xfinity/Comcast/Cox and others Xfinity/Comcast/Cox and others Comcast Xfinity Only (not compatible with other ISPs)
Downstream Frequency 108-1002 MHz 108-1002 MHz 108-1002MHz 108-1002MHz
Upstream Frequency 5-42 or 5-85 Switchable 5-42 or 5-85 Switchable 5-42 or 5-85 Switchable 5-42 or 5-85 Switchable
Thermal Design
Size/Dimensions 5.1 x 1.8 x 5.2 inches 7.2 x 7.9 x 2.2 inches 5.4 x 5.9 x 8.8 inches 6.1 x 3.4 x 10.3 inches
Spectrum Analyzer Web GUI Yes Yes* (depending on the FW version) Yes* (depending on the FW version) Yes* (depending on the FW version)
Warranty 1 YR 2 YR 1 YR 1 YR