Arris Touchstone Cable Modem CM820 DOCSIS 3.0 8x4

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.

This ARRIS modem CM820 replaced an absolutely IDENTICAL modem that I am paying $8/month to Comcast to rent. I bought this used but via Prime and it had a few small scuffs or marks. Who cares? It's a cable modem, it's gonna sit there and blink and you just use up your free interwebs.I had to call 3 times to Comcast to get it "authorized" but now it works great! DOCSIS 3.0 so should be relatively future-proof for a while. Tech support will say Billing must put it on your account, then billing says Activations does activations, whatever, just go ahead and waste 43 minutes of my time. Round & round we go. I can wait you out for $96 a year. I'll buy something nice for myself every birthday from Amazon!It will pay for itself in just less than 3 months. I called Comcast and they sent me a UPS Ground box prepaid so I don't have to drive 40 miles one-way to the only brick & mortar location in the State. My house happened to be the last stop for the UPS driver, so he waited an extra 30 seconds for me to tape up the box with the rental modem + cord. These are busy people, do not delay them. I gave him a tip about a good TV antenna and he was appreciative. *cough* cut_the_cord *cough* Call Sunday, box goes out monday with 2 day travel time, driver comes wednesday and delivers empty box, takes full box from me to make the cut-off that same night, 2 day travel time to return destination. By Friday I was chatting online with Comcast to get a credit on my bill.This Modem is worth your time & money folks! You can even check for compatible devices at:http://mydeviceinfo.comcast.net/Final thought: I do not have comcast phone, this is just a modem. If you use this modem you will lose your home phone service through comcast. Be aware of that fact. But there are other solutions like Nettalk, Ooma, etc for IP phones you can brew your own service. No reason to pay $39.99 a month when $29.99 a year will do.

Description said two ports, unless I’m missing something, there’s only one, luckily I only needed oneWorks good, no issues, great price

This modem is listed as fully supported by Comcast Xfinity and provides the speeds as advertised, most of the time. However, it randomly loses connectivity to the internet and only recovers after a full power cycle. After troubleshooting with the manufacturer, and they did a great job, it was determined it was faulty. Upon their further review and offer to replace the modem they said they could not ship a replacement as this was not covered under their warranty because it was purchased through a third party that is not an authorized reseller (not Amazon but the seller). Be careful, I bought it because of all the great reviews but my experience was very different.As a note, this was actually the second modem of this model I purchased because the first one I bought was a complete out of box failure. After 1.5 hours trying to get it to initialize on the Xfinity network, we determined the Ethernet port was bad.On to a different manufacturer and seller...I will make sure to get a warranty this time.

We have had Comcast for about two years on our current contract and every few months they jack up the price. We generally call them to complain about the jomp in bill, they waste a ton of time but our bill ends up getting lowered. The last time we called we realized that we are paying for the "rental" of the cable modem and for a 2nd cable box which we stopped using. Both of those were adding to their pockets and we wanted to address both. The cable box is easy - we will return it. The cable modem meant that we needed to get a new one. We were paying about 8 bucks a month so figured that anything that was less than 1 years rental was worth the effort. I read a lot of reviews with much of the super technical stull going right over my head. What stuck out to me were a) there can be some connectivity issues on Comcasts side and b) there doesn't seem to be a lot of difference between the cable models at a given price point. We went with the ARRIS since it has 3 stars on the Comcast cable modem compatability chart and I didn't want to get into a back and forth with them. And for less than 10 months "rental" I figured what did I have to lose?The modem was ordered on a Saturday and arrived on Sunday (OMG I love Prime). I had read where people needed to enter all sorts of account info and other numbers into the sign on screen so I decided to reach out to Comcast prior to connection. I gave them the SN and MAC address (one positive - ARRIS provides sitckers with this information on it that people without x-ray vision can actually read). They shut off my old modem (make sure you call them from a cell phone if your phone uses your Internet. Also make sure you give you kids a warning as nothing makes teens madder than losing their Internet even for 15 minutes). I disconnected the old modem and connected the new one. I had to wait about 25 minute with Comcast "setting things up" from their end. After a few times of the woman asking "can you get online now" and "have there been changes to the lights on the front of the modem" things connected. The link light flashes and all other lights stay on steady and green. Once things connected I re-attached my wireless access point and powered it off and then on again. Things seem just like they did when we were renting the modem. Except 8 bucks a month cheaper. Stop sitting there and click purchase.