ARRIS CM820A Cable Modem DOCSIS 3.0 (Latest Version - 1 Step Activation)

This is an Excellent Modem.Be warned, however, Comcast will NOT want you to use this modem, and may give you fits once you install it. They dropped my speed (which was supposed to have been 50, but Concast gave me some bs about the splitter that we have to use cutting the signal in half, which I bought because it seemed logical) from 35 Mbps down to 6 Mbps. Then, they started cutting the signal out up to 20 time A DAY! When I had the 1st tech come out, he did all he could, got no improvement, BUT the tech that he called on the phone said that there they were experiencing outages in the area. (Which did not make since, since I still had a picture on the TV, but what can you do?) He said he couldn't do anything else, and would have to come back again. He scheduled an appointment, but never came back.After about a week of waiting, I was furious and called again, requesting another tech agent come out. He did and did everything the 1st guy did, with the same uneventful results. I finally capitulated, desperate for a constant signal at the appropriate bandwidth, and agreed to have him install their New super-duper Concast Modem+Router, though it was going to cost me a monthly fee. Well, surprise! It gave me the same 6 Mbps signal! LOL So I said, "Forget it, just install mine again." They did, and IMMEDIATELY AFTER they Re-Installed mine, I got 50 Mbps! (Undoubtedly, it finally went though their system that they had installed their own Concast Modem+Router, just a minute after it had been uninstalled!) Then, it dropped back down too 5 Mbps!!!!!!I talked to the tech, and he was flabbergasted that I has the 50 Mbps screenshot to show him, and the current 5 Mbps speed to compare it to. He called the problem "systemic" - meaning there was nothing he could do, and basically confessed that it had to do with the person he called on the other end of the line, who AGAIN claimed that there was an outage in the area (because that is Concast's default excuse). He also said that he had installed plenty of splitters and a single splitter would not cut my internet speed in half. So, he left.Then I called Concast again, late that Saturday, and I was Irate. I told them that I knew what they were doing, that there was NO REASON my speed should go up to 50 then drop down inexplicably to 5 other than the fact that THEY were the cause of the problem. I asked to make certain that the call was recorded. I demanded that it be played for a supervisor. And I threatened a class-action lawsuit if they did not fix it. Oh! And I also requested that another tech come out and Re-Install their New super-duper Concast Modem+Router. (I did not say so, but I planned to get the next installation on camera.) Then, after the call, I took the survey that they'd asked me to take, and I trashed their customer service and said that I would not recommend them. When they asked why, I recorded a very irate message for them.Interestingly, the tech that I requested to come out and install the New super-duper Concast Modem+Router never came. However, my speed did jump up to the Blast speed of 75 Mbps (which is what it is now supposed to be), and it has remained there with little to no interruption.

I was renting a Cisco DPC3008 modem at $8 a month because my old cable modem was at the end of product life and was too slow to use with my Cisco (Linksys) E4200 router and my.switching over to digital TV.I made sure I purchased a new one because I had read all the horror stories people had posted on Amazon had having problems with buying used modems only to find when they went ti install the modem they couldn't because it was showing it was still being used somewhere else and them getting stuck with it!!Ordered on Monday and got Wednesday. I unhooked the rental modem and hooked the same cable and ethernet into this one plugged the power in and within a couple of minutes the instructions from Comcast on how to get it registered was on my computer screen. Got logged into my Comcast account and hit the continue button and got a "Page Will Not Download" message! Tried to go back to start over and computer kept popping up with a "page not on server" message. I though great this thing is not going to work.So I called Comcast tech support only to find out the modem was fine the problem was Comcast was down. The guy gave me a emergency service number to call and the young lady who took the call at the emergency service center was wondeful!! She took the MAC address and sent me an activation signal and then talked me through what was going on. There was a delay of about 3-5 minutes while a firmware update installed and she stayed on the line till it was up and running. I had read several complaints about firmware not up dating but this did it on it's own.I see no difference in the way things are between this one and the Cisco DPC3008 I was renting from Comcast other than $8 in my pocket each month. The real test will come when my kids and grandson comes to visit. We have streaming on all the TV's plus laptops and desktops. There is always a couple of people online plus at least 2 TV's going from about 8 in the morning till 10 at night. That will be the real test if can handle the load then. With just me and the wife there there is little demand on the modem.I will update this after the kids leave after their next visit. But over all I am quite pleased with the ease of setting this up if Comcast hadn't gone down I could have been up and running within 10 minutes of when I powered it up. Even with having to call two different service departments I was still up and running within 30 minutes from the time I plugged it in the first tine.

I was looking for a modem that would work with Optimum Online. This did not. Call customer service to get it working and couldn’t.

I just got Comcast blast and I get 55 mbps with this modem. Also tried the motorolla sb121 and sbg6580 whichever has the router too.I did want a router but I think I will buy that separately now. Just like the more understated design and its less of a shareholder profit based company. I paid the $62.50 which is cheaper than motorolla and like I says the speed having tested both of them in the last week is pretty much identical, so if anyone tells you there is difference either way, not true.Not sure which is more durable or will last longer, but looking at the design, the arriss seems to be more based on function and not looking "cool".Had the Comcast performance at 22 mbps but that is really their bait and switch service, because although it does run at the advertised speeds, if you use your pc as much as I do, those speeds are painfully slow.After using this for a couple days, I would continue to say it is better than the comparable motorolla products. It does need to be reset every now and then with heavy usage. The motorolla however would sometimes take a 1/2 to get going again, this does not. Nice product for money, no nonsense.