Looking for a list of Cox compatible modems and cox approved modems? Don't waste your time. Check out Motorola SB6121 - the fastest Cox modem available today here.

1. Motorola SB6121 – The
Fastest Cable Modem For
Cox Cable
By Halton James Gallinger
If you are looking for Cox compatible modemsas a new modem or to replace your existing Cox rented
modem,then you should seriously consider the Motorola SB6121 Cable modem. However the first thing
that comes to mind is that is this modem one of the Cox compatible modems in its list of Cox approved
modems. Well the answer is yes; as such you will not have any problems using this modem with Cox.
I will not bore you with the technical aspects of the Motorola SB6121 but if you are really interested,
then you can go this this site http://www.SB6121.com which has tons of information on this modem.
Here is a summary of the features and functions of this Cox approved modem:
Brand Name: Motorola
Model: SB6121
Hardware Platform: PC
Width: 6.40 inches
Weight: 1.40 pounds
Up to 160 Mbps downstream, up to 120 Mbps upstream
Front panel, easy to read operational LEDs to indicate status and simplify troubleshooting
IPV6 support - latest Internet communication protocol
Rear panel color coded for ease of installation
Key Features Of The Surfboard SB6121
Plug and play installation
Front panel LEDs indicate status and simplify troubleshooting
Multi-language user guides
Supports standard internet software
User-friendly online diagnostics
To give you a level of comfort to make a decision that the Motorola SB6121 is the right cable modem
choice for you to use with Cox, here are some owners of the of the modem sharing their experience:
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2. Very Good DOCSIS 3.0 Modem - Works with Cox
Communitcations, October 6, 2011
By MG
I bought this modem after my 6.5 year old Terayon died a slow painful death. That is a long
story. Well, I have had this modem for 2 weeks so far and it works great. It does run a little
warmer than a DOCSIS 2.0 modem(but not hot), but I think it is well worth it. I also keep mine in
a well-ventilated area, so no worries. I have a mid-tier plan with Cox Communications and this
has cured all of my problems.
Oddly, I saw a lot of new people pop up when searching for wireless networks around me. I
assumed that I was losing bandwidth to the increase in use over the past year or two. It was
clearly the modem. I was to the point prior to this purchase of being unable to do any gaming
and netflix streaming for the past two months was a gamble.
Now, all is well and all of my services are working as well as I would have hoped. I have regularly
tested on speedtest.net, just to see what I am getting now. A rough average for me is:
50 Mbps down
5 Mbps up
30 ms Ping
However sometimes it is a little higher or lower, for instance yesterday I downloaded an 80MB
podcast and it took 8 seconds, so do the math on that. and it works out to about 80 Mbps
download. So, I do believe that if you have the bandwidth in your local area, future proof with
DOCSIS 3.0
Lastly, the design of this cable modem is great. It is compact and attractive, even though I have
done a good job of hiding it. To quote my wife "its really cute"
Very Good Modem, October 23, 2011
By AZ Roger
I updated my Motorola modem from DOCSIS 2.0 to a Motorola DOCSIS 3.0. I had done some
research on different brands and DOCSIS 2 vs 3, and was pleased with the product. I had a very
noticeable improvement immediately in download speed via Cox cable.
The modem was easy to install and get updated the logged into the Cox records (by calling Cox).
It gets slightly warm, but probably less than my old one - as it has better ventilation holes. It
was delivered in just a few days - faster than expected.
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3. SB6121 is just plain FAST!, February 3, 2012
By azloafer
I replaced my old Motorola SB5101 with this newer SB6121 after reading some articles that said
the 2.0 modems could be slowing your cable connection down even though you are paying for a
high speed connection. Well, I gave it some thought, after all this modem is not cheap. OK, I
went for it and ordered the SB6121 after reading all the reviews.
While waiting for the shipment I did a speed test at an ISP approved site on the Internet. I did
the test at 8:00PM which is a really busy time. I logged the results and saved them so that I
could do the same test over with the new modem at the same time of the evening. I should add
that I repeated the speed tests several times so that I could weed out any odd incidents. It
turned out that nothing strange happened.
The new modem arrived and setup was easy. The first time I attempted to connect to the net
with Cox Cable a screen came up that said I should call Cox for help. I did and Cox needed three
different numbers from the modem label. They reset the modem and added it to my account
and everything was working within 15 minutes. They did all the work on their end. Then came
the speed test to see if I wasted my money or if it was a good investment.
First the old modem DOWN SPEED: 19:41 Mbps UP SPEED: 8:08 Mbps
Now the new modem DOWN SPEED: 21:30 Mbps UP SPEED: 16:16 Mbps
Now you can see that there is not much of a change in the down speed, BUT the UP SPEED,
which is the speed with which you connect to any site on the net, had doubled! In real world use
what does this mean?
I can tell you that it is STUNNING! It made me say wow! My wife, sitting in another room, said
what is going on? I told her to turn her laptop on. She is connected wirelessly. I said just connect
to several of your favorite sites and see if you notice any difference in the connection.
In a few minutes she was saying, "Gee, that is faster!" The bottom line is that the Motorola
SB6121 3.0 Modem is worth every penny. If you are using a 2.0 modem and are paying for a
high speed cable connection, the newer 3.0 modem will be what you need. Google for speed test
sites that are free and compare your present reading to mine if you have a 2.0 and that should
tell you what you should do. Best money that I have spent in a long time.
Excellent choice for new modem, May 8, 2011
By Michael B
I has having good success with a 3-year old Motorola Surfboard modem, but had been reading
that newer modems = faster speeds without having to upgrade service. I checked with Cox
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4. Communications to see if the SB6121 was compatible with their service and they said it was so I
ordered it.
Plugged it in and called them with the MAC & Serial numbers - was up and running in 6 minutes,
including 3 minutes of hold time and a minute to restart my router and computer.
Ran a speed test through speedtest.net prior to switching modems. Old modem had PING of
27ms, 23.77Mbps download, 2.62Mbps upload.
New modem test 10 minutes later: PING 18mx, 41.19Mbps download, 4.33Mbps upload.
Not bad for a $100 investment and no additional charges from Cox.
Highly recommended if your provider is setup to operate with this modem.
Great Cable Modem, May 23, 2011
By Chipbuilder1
This Cable Modem works just as advertised, it is easy to install and just works. I am getting the
best download and upload of data I have ever seen from the COX network.
This Modem Rocks!, June 6, 2011
By EUSCFZ
I am using this modem on cox Cable in orange county.It is not yet on the approved list, but the
SB6120 is.
As soon as I hooked it up, my data rates were much faster.
Almost doubled my speed, December 20, 2011
By Video Services OfVa
Received today and am using Cox cable Premier speeds. About 20mbps down and 5 up. Hooked
this up and 2 tests at Speedtest dot net, I am now getting 37mbps down and 5 up. So, I'd say it
did exactly what I wanted.
That's my experience anyway. Good luck
Working Flawlessly, January 2, 2012
By M D Baxter "mike2400"
This modem is working perfectly. It has been 100% stable since it went online with no resets or
restarts. Like something from RONCO you can just set it and forget it. Upstream and
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5. downstream speeds have been consistent with what I am paying for with COX and sometimes I
am even getting faster speeds then I have paid for.
I feed 6 live radio stream through this modem for Radio Reference and LiveATC and I can
download HD quality movies through VUDU and other services with no stuttering or buffering. It
looks and sounds like a blu ray on the home theater. You will be very pleased with this modem.
Great Modem, January 28, 2012
By Virginia M. Nyre
We use Cox for High Speed Internet and this modem gives us great speed and reliability. Since I
installed this modem we have not experienced any issues with accessing the Internet.
Works Great, February 13, 2012
By C. Athan
Cable modem works great on my COX cable system no problems setting it up.Connected to a
router for wireless connections in home network.Not much else to say all works as it is designed
to do.
The Verdict
The Motorola SB6121 is a great modem as can be seen from the experience of the owners of this
modem. What makes it great, especially for Cox subscribers:
One on the list of Cox compatible modems
One on the list of Cox approved modems
DOCSIS 3.0 approved modem – very fast
Protects your investment as you do not need to change your modem for a long time as it has the
capacity to handle the speed
Backward compatible
Solidly constructed modem
Easy setup
Very stable
Most owners noticed visible increased in speed over their existing setup with this modem
Click here to buy Sb6121.
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