Customer Ratings & Reviews

This replaced a Comcast leased cable modem. I took it out of the box, disconnected the leased modem, connected this one, and started up the computer and the modem. Within two minutes, a Comcast self-install screen came up. I entered my account number and phone number, accepted the terms, and within 3 minutes this modem was installed, configured, and running perfectly. And with a very noticeable speed difference over the leased Docsys 2 modem. Never had to call Comcast. This is a no- brainer.

Very easy to set up. Just call TWC and give the MAC address to activate. It pays itself after a few months and will support TWC 100 Mbit plan in case you want the highest bandwidth. It also indicates if channel bonding is enabled by ISP or not. In this modem, blue = channel bonding is used while green = 1 channel active only. I have a 15 / 1 plan and the download lights are blue while upload lights are green. There's also blue and orange lights for Ethernet where blue = 1 Gbps link speed while orange = 100 Mbps link speed. Also, from the modem's web page, this modem increased my SNR from 37.5 dbm (rented modem) to 39.5 - 40 dbm which is a bonus.

Replaced an old D-link DCM-202 that was dropping the connection easily more than a dozen times a day. Installed this quickly working with Charter and it is working perfectly. No dropped signals and is always performing optimally. Speed tests on the internet says our down load speed is about double that of the old D-link. Much higher than what we are supposed to be getting. The internet does not appear to be faster though, but it is now consistently blazingly fast. The old D-link would sometimes slow to a crawl. The only way to fix it was to restart it. I'm very satisfied and would recommend to Charter subscribers. My wireless router is the Belkin N750 DB.

I bought this cable modem when my comcast supplied modem died. I ordered on-line and picked up in-store on my way home from work. The actual installation was very simple and the only slow down was I had to call comcast to activate the new modem because the comcast website was not working properly. After a 10 minute call everything was working properly and my internet speeds are the best they have ever been.

I decided to purchase this modem for use with Comcast after my previous DOCSIS 2.0 combination router/modem had many performance issues with locking, needing multiple resets, etc. Since I've started using this modem with a separate router, everything has been running perfect. My speeds are excellent and I rarely ever have to reset the modem for performance issues. It was easy to setup. I only had to call Comcast to give them the MAC and plug it in and everything was good to go. I would highly recommend this modem to others.

I went out and bought this after having a problem with another cable modem/router combo went on the fritz after 2 months. This was about half the cost of the other one i had bought originally and works way better. Side note: in order to get WiFi again i did have to purchase a router to go with this unit. This unit is rated 3 stars for Comcast and the other more expensive units are ranked 1 star for Comcast support. so do yourself a favor and cheap out on this one. You'll love the fact that you did.

I got tired of paying rent to comcast on a slow box. Purchased this for my home at first. Speeds increased greatly. Recently my business class service slowed down. Purchased another one of these for work. My upload average went from 4mps to 30 mps. Purchasing one will pay for itself in just over a year..... Well worth it ....

Works well so far. Happy with motorola modem purchase.

This was easy to set up, Charter is my ISP. It is fast and is able to power all of my devices. I do play some on-line games and it is plenty fast to prevent lag. Seems faster than the modem provided by the cable company.

I brought it home and hooked it up and got ready to call Cox to have it installed. I had the computer on and firefox open while reading the book all of the sudden Cox was online and they asked a couple of questions and then it was done and installed, sweet. I was using a SB5102 that was 10/100 and the SB6120 is 10/100/1000 so more speed there. I checked my speed on speedtest.net before and after. My average after 4 test was, DL before 13.84 Mbps and after it was 24.12 Mbps. UL before was 2.99 Mbps after 5.25 Mbps. This is an improvement of 73% DL and 56% UL. This is better than the plan I have from Cox.

Upgraded to High Speed internet 50Mb/s and test my speed and it was correct.

I installed this modem, and it boosted my download and upload speeds 3 times over the modem I was using which was several years old. When I connected it to Cox High Speed Internet Premium the upload and download speeds went from fair to excellent. If your video downloads slow or are interrupted from time to time I would recommend this modem.

This unit works wonderfully and as advertised-once it FINALLY gets online.Which can take FOREVER after it is provisioned by the ISP.I was told by one of the people I spoke with at my cable company (RCN) who owns this same model,that it tends to take these modems a long time to actually go online once they get provisioned by the ISP.They told me that one of their customers modems took all night to finally lock in and go online.In my case it took about an hour.In the meantime it will cycle on and off and on again until it finally locks in and goes online.If you buy one of these and call your provider,just be patient.They will likely think something is wrong with it.I actually returned one and got another before we got it to work.Although typing in the modem's IP address in your browser and checking the settings with the help of the tech people at your ISP will help a LOT in determining if anything is wrong.

I bought this router for the same reason many others have- because with it I save $7 bucks a month on my comcast internet bill. It is easy to set-up. Simply plug in all cables and call Comcast and tell them that you bought your own modem and want to activate. They will help you from there. Overall, the entire process took about 15 minutes, and that's including being transfered to the local equipment office to arrange for a pre-paid box be shipped to me so I can ship them their modem back. As far as performance increase goes, I did a Pc internet test and am getting on average 15-20 Mbps d/l and up to 4 Mbps u/l. I imagine that is an improvement, but I also replaced my router at the same time. With both of them, I definitely see an improvement.

I wanted to stop paying for my cable modem with Comcast. I researched modems and came to the conclusion that this was the best one for the price. I am particularly computer-challenged. Nonetheless, setup was exceptionally easy. I haven't had a single problem with it since installation.

Time Warner's rented modem ($5.99/month) gave me 22 Mbps download speed. My new SB6121 modem now gives me 54 Mbps. Time Warner's modem gave me 2 Mbps upload speed. The SB6121 now gives me 5.4 Mbps. And as soon as I can return Time Warner's modem to one of their offices, that will eliminate their irritating rental charge. I will then make my money back on the cost of this SB6121 in 12 months.

Setup was flawless with Comcast and working great. After plugging in the modem and trying to access a website, Comcast's automatic provisioning webpage came up and after walking through the wizard everything worked great. Speeds are much better than the garbage you can rent from Comcast for $7 mo.

I plugged it in, called the ISP to register the HFC MAC address and serial number and it just worked. Being a DOCSIS 3-compliant modem allows it to achieve maximum performance on the Comcast (Xfinity) network. No problems.

I wasn't sure what to expect moving to cable internet service from being a DSL user for several years, but this modem worked perfectly out of the box and my service was up and running with zero hassles.

I was using a Motorola cable modem that I'd owned for at least 8 years, and I was having frequent problems with my internet connection simply dropping out. This required a re-set of the modem and with WiFi router. This modem has been a significant upgrade, providing speeds that are consistently higher than what I was getting with the old modem. More important, it is reliable and I have not had any problems losing the signal since upgrading. Comcast was able to authorize it with no problems.