Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem

I have Time Warner internet in the Raleigh/Durham area of NC. This is a DOCSIS 3.0 area.

My download speeds have been shockingly unreliable ever since I started my internet service about 6 months ago. It is supposed to be 20 mbit down. Sometimes, it is actually better than this (25+ for short times), but more often than not, it is much worse (at times < 5, usually around 10-12). It also fluctuates wildly on a minute-by-minute basis. One minute I'll have great speed, the next it crawls. Even during a single speed test, it would fluctuate between about 5-25 mbit.

TWC support was predictably unhelpful. The best I got from them was "that should not be happening." I pointed out that their own FAQ page says that a DOCSIS 3.0 modem is required for my service tier (so-called "turbo"). They said no, the old DOCSIS 2.0 Motorola SB5101 they gave me was fine. I got the same BS from the "normal" reps as well as the so-called "level 3".

I asked if they would give me a DOCSIS 3.0 modem, even though they claim it is not "required". They said no, I would have to upgrade to "extreme," which would add $10/month for the service and another $2.50/month for their DOCSIS 3.0 gateway.

So instead of doing that, I bought this modem (which is on the TWC approved device list). I called them, gave the MAC address, and I was up and running. When the modem connected, the downstream LED turned blue, which according to the manual, means that the channel is bonded. This is a very good thing.

With this modem, I get 20 mbit on the dot, 24 hours a day. Every speed test I have run confirms (including the 200 MB test on testmy.net). Last night, I downloaded about 15 GB of data with a sustained 20 mbit rate the entire time. It's pretty amazing how effective it is.

My speed is never ABOVE 20 anymore, but it is NOT BELOW either. I believe that the channel bonding makes it easier for the ISP to enforce bandwidth caps, but it also makes the connection more reliable. I'll take that deal any day.

I HIGHLY recommend this modem for TWC customers in DOCSIS 3.0 areas. Don't believe the customer service reps -it absolutely is required. It sucks that TWC won't provide the hardware we actually need to fully use their service, but that's just the way it is.

As many of you, I am a Time Warner customer. I was disappointed with my bandwidth speed. I was paying for "Turbo" at an extra five dollars per month but was't seeing an improvement (I tried on heavy and light usage days / periods). So I purchased this cable modem, after reviewing the compatible modems, on Time Warner's site. Be sure to check the list of modems allowed by your provider FIRST.

I opted for the SB6141 DOCSIS because it is has the IPV6 addressing system, is backward compatible and its channel bonding technology to boost my bandwidth speed. The IPV4 addressing is used up (predicted to be end of this year) the internet community will be going to the new IPV6 addressing system.

Granted bandwidth is limited to the CAP set by your provider but your equipment plays a part. Before I bought this modem I was using one from Time Warner. My best speed test (using speedtest.net) was 5.94 Mbps download and 1.92 Mbps upload. As of this morning, my latest test, shows 34.35 Mbps download and 1.92 Mbps upload. The upload limit is obviously kept by Time Warner to discourage uploading of large files (music libraries ,etc.).

It is built on the DOCSIS 3.0 standard (Data Over Cable Service Interface Specification). This is the latest version of DOCSIS. It also means that it uses channel bonding technology to gain access to the unused bandwidth capacity available on your network, in effect, boosting your bandwidth speeds.

The modem has 8 download and 4 upload channels. This means that the provider can (doesn't but could) offer data rates over 300 Mbps download and over 100 Mbps upload (at least not to home users). Each channel is capable of 40 Mbps, theoretically, for a maximum of 320 Mbps. But your provider "caps" the maximum at a much lower number. On a home system if you are getting 30+ Mbps you are doing extremely well.

I have 12 devices running off my home network so I am pleased with the results. I also bought a Cisco Linksys E2500 dual band router which basically places six on each band.

Just an FYI: You have to call Time Warner, go through the lengthy process of explaining that you have bought your own modem to replace their modem. You want to have it added to their network. You will have to provide MAC address and SERIAL number of your device, name of the modem including model number and then wait up to two days for them to make the switch. I know, ridiculous right?

Another FYI: The power light at top will be green, the second light blue, next two lights green and last light blinking orange (GigE-RJ45) unless you have Gigabit capability (offers up to 1 gig Mbps transfer speeds). You need a gigabit router, gigabit ethernet card to take advantage of the increased speed AND a provider that offers it. The GigE-RJ45 allows you to obtain Gigabit rates using the same 10/100/1000 ethernet Cat 5e or 6e cables instead of needing Fiber Optic cable. Its geared toward small to medium sized business owners.

Pros: offers AES enhanced AES encryption security, channel banding technology, GIGe-RJ45 port, compatible with EuroDOCSIS, has built-in filter to reduce interference from MoCa signals, easy to access menu, easy to set up and cost less than its predecessors.

I would definitely recommend this product and suggest upgrading to a dual band router.

Buy Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem Now

I just bought this modem and got rid off the SBG6580 due to it's weak wireless signal, plus i already own a good dlink wireless router.

Called time warner cable, gave them the mac address and it was up n running in a less than a minute =] it totally rocks!

TWC was charging me 7 bucks a month for the sb6580 rental fee, i live in los angeles and i can confirm this new modem works with TWC internet.

Read Best Reviews of Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem Here

*** PLEASE CLICK "YES" THIS REVIEW WAS HELPFUL SO IT STAYS VISIBLE AND NO ONE ELSE IS DEFRAUDED ***

I'll spare you the long, sad story of my hard-to-diagnose internet connectivity problems, and jump to the end. The week before last, my cable modem (the Motorola SB6141 I bought on this page) started "flapping" provider-speak for constant adjustments associated with periodic disconnections from the internet. The modem would connect for 5-10 minutes, then disconnect for 1-2 minutes, then reconnect for 5-10 minutes, then lose connection for 1-2 minutes, on and on, 24/7. The Time Warner Cable guy who came last Friday (about the 12th guy who'd been here recently) said, "Your modem is flapping." My modem had done this once before and I had reported it. I'd even kept a log of on and off times, and shown it to the previous cable guy who came in answer to my service call. But that guy just looked blankly at my log and shrugged. The cable guy who came last week, however, knew what it was and what it was called: "flapping".

He said that usually when he sees flapping, it's caused by a faulty modem. He swapped in a TWC modem, and said to call Level 3 Tech Support in a week to ask if there had been any flapping. I can tell myself (the hard way) if there has been any flapping, and there has not. I've had a week of solid connectivity (for a change). But I called anyway today, and the Level 3 Tech Support guy confirmed: my connection hasn't wavered. There have been no service interruptions, no flapping. The problem was definitely due to a faulty modem.

This surprised me because I think of Motorola as a good brand. I wouldn't have thought that a brand new Motorola cable modem would not work properly. But the evidence was indisputable, so I called the Motorola Warranty number and requested a replacement. Now here's where it gets really interesting.

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The Motorola Tech Support guy who answered the phone asked me where I bought the cable modem. I told him Amazon. He then asked a very odd question: "What color is your cable modem?" I said, "Black." He said, "Then it's a used modem. That's probably why you're having problems. We're seeing that a lot."

Notice that the black Motorola cable modems are not sold by Amazon directly they are sold by other merchants through Amazon. The SB6141 that Amazon sells directly is the white one: Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem Retail Packaging White (The white and black modems are functionally the same. Motorola colors them differently to identify their distribution channel.)

He went on to explain that the black modems are sold by Motorola ONLY to cable internet providers like Time Warner Cable, and the white version is the one meant for end users. But he knows from warranty calls that black cable modems, advertised as new, are being sold to end-users on Amazon and eBay. These cannot be new because no one but a cable internet provider can buy the black modems new. So where did these sellers get the black modems? They only could have gotten them used from cable internet providers. That also explains how they're able to sell them below retail price. The seller on this page sells the SB6141 for $11 below retail. Another seller offers it for $22 below retail.

Selling AS NEW heavily used modems that by-definition are prone to failure constitutes fraud.

DO NOT BUY BLACK MOTOROLA CABLE MODEMS. THEY WERE PREVIOUSLY OWNED BY A CABLE INTERNET COMPANY, AND LIKELY TO HAVE BEEN HEAVILY USED. THEY ARE *NOT* NEW, AND THEY ARE PRONE TO FAILURE.

Want Motorola SurfBoard SB6141 DOCSIS 3.0 Cable Modem Discount?

The SB6141 is listed on TWC's list of approved modems. No issues with install. Easy to access menu to view power levels. Fast and works as advertised. Highly recommend.

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Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem

• 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

Out of nowhere, I was having excruciatingly slow internet speed on Comcast. The Comcast tech advised that my Motorola SB 4100 was at the "end of life" and that I should upgrade. Skeptical, I purchased this modem which is a DOCSIS 3.0 (and backwards compatible) modem. It worked. I went from a 2mbps download speed to over 17mbps. What a difference. There was one installation glitch that you need to be aware of. When you hook up the modem (connect the coax cable, connect the ethernet cable, and plug it in, that's it), and then try to get online, it will direct you to a Comcast self-activation screen (no other site is available). After entering my account number and phone number and hitting the "next" button, I got a blank screen, and nothing happens. So I called Comcast and they said that usually happens if you are doing an upgrade; it mostly works only for a new service connection. However, it is a simple matter to give the tech your MAC address and the serial number. After about 5 minutes, while he stayed on the line, it came alive, no problem. BUT, here's the thing: the serial number they need is the CUSTOMER serial number. This is only found on the bottom of the Motorola box the modem came in. This is different from the "S/N" serial number that is on the label that is on the instruction sheet and on the bottom of the modem itself. The customer S/N has letters in it; the regular S/N has only numbers in it and is too long. My first Comcast tech didn't know that and it took a day to sort it out. Other than that, it works well with my iMac and Apple Airport Extreme Base wireless router. Enjoy

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I have tried both the SB6120 and the SB6121 and the signal levels and speeds were the same on both.

The SB6121 is a little smaller than the SB6120 but runs much warmer than the SB6120. Looks like they tried to cram too much hardware into too small of a space.

My SB6121 did not come with the power save button (it's listed as an optional feature), so about the only difference between the two models is the design. Both the SB6120 and the SB6121 use the same firmware: labeled SB612X.

So unless you want the different looking LED lights and a smaller and warmer box for a higher price, stay with the SB6120.

As far as speeds are concerned: the multiple channel bonding on these DOCSIS 3.0 modems is nice for sustained constant speeds. It also makes it easier for your ISP to enforce the speed cap if they choose to do so (Comcast in my case does). I was getting 20+ Mbps down and 3+ Mbps up on my old Linksys DOCSIS 2.0 modem, however that was the peak when the transfer first started, then it would taper off.

The DOCSIS 3.0 modem stays right at the 12/2 ceiling of my speed tier, but at least the speeds stay right up there and do not drop off after a few seconds.

Read Best Reviews of Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem Here

Bottom line: this is a great modem and it works with Comcast. Comcast just doesn't have its act together. This modem is not only on their approved list, it has a three star rating, which, according to Comcast, is "the highest and most thorough level of testing." When the cable installer got here (I got a new line installed), he said that this modem was NOT on the Comcast list. Since I still had my DSL line working, I showed him that not only did Comcast approve the modem but that Comcast thoroughly tested it. He had to call the "office" to activate the internet service. The "office" didn't want to set up internet service for this modem; the "office" stated that this wasn't an approved modem. Well, he recalled the "office" and got someone else and they set up the service. I've been happy ever since. I'm supposed to get up to 20 Mbps download and 4 Mbps upload. My computers are connected wirelessly. Speednet states that I am getting 20 to 25 Mbps downloads and the upload speed is between 3 and 3.5 Mbps. I've gotten similar values with speakeasy and other internet speed testing sites. I have a lot of devices connected: three computers (wireless), two TVs (one wired, one wireless), three different game consoles (connected to the wired TV), two Nintendo 3DS (wireless), one printer (wireless), and an iPod Touch (wireless). At times all of these devices are running at the same time the computers are streaming You Tube videos, one of the TVs is streaming Netflix, etc. The modem handles all of it effortlessly. I'm really pleased with this modem.

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I felt compelled to write this to help those who will encounter the problems I faced (and mentioned here). I'm one of the many people who wanted to avoid renting a modem from Comcast and bought this modem based on the stellar reviews, only to find that on the day of installation/activation that it "didn't work". Didn't work meant experiencing the same symptoms that's been mentioned here several times "modem connects but then resets/power cycles/disconnects itself within a few minutes." This happened to me on the day I activated my Comcast internet. The technician spent 1.5 hours trying to figure it out and ended up loaning me a Comcast modem (Motorola SB5120 DOCSIS2), which came up almost instantly and activated just as fast (go figure). He suggested I return this modem as it was defective, in his opinion. I didn't like this since the probability of this was very small. But I saw what I saw and could not get past the first page of Comcast self activation screen with this modem. Before the web page for self activation could proceed, after typing my account info and phone number, the modem would conveniently lose connection. At one point I did get to the next screen where it was scanning for devices, but the modem cut out thereby hanging the process. The modem was packed up in the box for return to Amazon when I couldn't shake how much this bothered me and by my bad luck. So I came back here and read pretty much every review. What I found was there's several people who experienced the EXACT same symptoms while trying several of the same modem. There were two reviews that stood out. One was from a person who mentioned the Comcast technician moaned when he saw it was this modem, indicating that the technician was aware of difficulties using this modem. The person mentioned that after 70 minutes of trying to get the modem to connect the technician advised him to leave the modem powered on and hooked up for awhile and to try activating later. The person did this and was successful in activating the modem. The other review was from a person who was admirably persistent. His review talks of several attempts to connect and refusal to accept that the modem was defective. He ended up leaving the modem power on and connected overnight so the modem could "download firmware". The next day he was able to activate after two attempts with Comcast self activation process. Lastly, I noticed for me that if I left the modem power on and connected but make no attempt to activate it via Comcast web site, the modem retains connection (via indicator lights) for prolonged periods of time. It only seems to lose connection when I try to activate. Based on this I felt something was broken with Comcast activation process specifically for this modem or perhaps Comcast was intentionally making it difficult to activate this modem to convince customers to rent a "reliable" modem from them. To be honest, it almost worked for me. After sitting there watching the technician agonize trying to get the modem to work, I was tempted to rent the modem and move on with life. So as one last hail Mary attempt, this is what I did:

1. Took the modem back out of the box and left the Motorola SB6121 power on and connected to cable outlet overnight just to entertain the possibility that some firmware or info needed to be downloaded to the modem and that for some reason it took a long time to do so.

2. The next morning I tried Comcast's self activation process.

3. Every time Win7's network icon in the lower right corner of my screen indicated that a internet connection was established (vs. exclamation mark) I immediately opened a IE windows and started the activation process with my account and phone #. The modem still lost connection when I did this but I kept on trying.

4. It took me about 4 tries to SUCCEED. Each time I tried, I started back on the account and phone # page. But each time it got further and further in the activation process.

Attempt #1: Account/phone # screen -> Retrieving Device Information -> Modem lost connection.

Attempt #2: Account/phone # screen -> Retrieving Device Information -> List of devices detected (screen showed my MOTR SB6121 modem and a DTV box both shown as "inactive" -> Modem lost connection. (A thing to note here is that Comcast's activation system could specifically identify this modem. This meant it was in their system and their system was able to communicate with it)

Attempt #3: Account/phone # screen -> Retrieving Device Information -> Listing devices detected -> Clicked "Rescan" device (modem)-> Hit "Next" to activate then got to screen where it said "Activating Device This may take 10 minutes" -> Modem lost connection

Attempt #4: This isn't a real attempt because all I did is leave the web browser in the previous "Activating Device" screen and waited for the modem to re-establish connection again. I stepped away for a few minutes and when I came back I got a screen that stated "Device Activate" (and some other instructions that didn't matter) Hallelujah! Also note, NO phone calls had to be made to Comcast to activate this modem.

At this point, this modem which was losing connection all the time before, now had a seemingly rock solid connection!!! I'm using the connection now with this modem as I type this. I've did some basic testing, streamed video, surf the net,etc. NO LOSS OF CONNECTION! I did a speed test and I'm getting 25Mbps down and 3.8Mbps up.

Based on my experience so far, it is in my opinion that this modem works and is as good as what the majority of the reviewers here have stated. The problem lies in Comcast's self activation process which is suspicious. What doesn't make sense to me is the fact that modem can hold a solid connection if you didn't attempt to activate and after it's successfully activated. It was only when I tried to go through the self activate process that I saw problems. I can't say much about whether step #1 helped but it can't hurt to try. I mentioned it only to inform people of what exactly I did.

I truly hope this helps people. Amazon is top notch. This modem is now doing what it's suppose to do with no issues. I'll come back and update this review in about a month to report if it still holds true. I think it will but we'll see. And lastly, thanks for the people who shared their experiences here. If it weren't for them I would have returned the modem back to Amazon and go through the hassle of finding another modem or giving in and renting one from Comcast. I'm trying to pay it forward with this review.

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12/14/2011 Just received the Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem today. Followed the self-install instructions included with the modem, using Comcast internet, and a Medialink Wireless N router, and was up and running in 20 minutes. Note; also used a Windows OS laptop for the setup, with Internet Explorer.

Here's how my setup went. Disconnect your old modem. Connect the SB6121 modem to your internet coaxle cable. Now connect the ethernet cable to both the SB6121 modem and your computer. Power up the SB6121 modem and wait for all lights to stop flashing (must have solid lights), then power up your computer. Now, open Internet Explorer browser and wait for the Xfinity screen to automatically show up on your Internet Explorer's screen. Enter your Comcast account number and the phone number associated with your Comcast account on the screen, where asked, and press next. The SB6121 modem will then be automatically identified and recognized. Press next to accept the Motorola SB6121 cable modem, then wait a few minutes for the next screen to show up while the information is being processed, then press finished. 3 screens total. Disconnect the ethernet cable from your computer and connect it to your router. Now, power both the SB6121 and your router off and wait 10 seconds. Now, power the SB6121 modem on and wait for all the lights to show themselves. Now, power on your router. You should be able to go online wirelessly. Literally that simple. The Comcast Xfinity self-install screens did not ask me for a MAC address or a serial number. Total time about 20 minutes to remove the old modem and install the SB6121. Best part, no having to call tech support and no frustration!

I was quite surprised at how easy the SB6121 was to install, as it seems like I'm one of those guys who takes 2-3 hours to hook anything up. Seems like there's always that one thing I didn't know, or think, about, and I'm usually on the phone with tech support for a while having a lackluster time. I replaced an old Comcast RCA modem which I had no problems with, but was tired of renting from Comcast at $84 per year. The SB6121 will pay for itself in a year's time, is a 3 docsis modem versus 2 on my old modem, and works well thus far.

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