


🚀 Unlock lightning-fast internet with ARRIS CM820A — your gateway to seamless streaming and productivity!
The ARRIS CM820A DOCSIS 3.0 cable modem features 8x4 bonded channels for superior throughput up to 300+ Mbps, built-in MoCA immunity filter to reduce interference, and meets industry surge and radiated immunity standards. Designed for easy one-step activation, it delivers reliable, high-speed internet for home and small business users, helping you save on rental fees while enjoying stable, fast connectivity.
| ASIN | B008GG78FU |
| Batteries | 1 Lithium Ion batteries required. |
| Best Sellers Rank | #12,160 in Computers & Accessories ( See Top 100 in Computers & Accessories ) #61 in Computer Networking Modems |
| Brand | ARRIS |
| Color | Black |
| Customer Reviews | 3.9 3.9 out of 5 stars (767) |
| Date First Available | August 19, 2013 |
| Is Discontinued By Manufacturer | No |
| Item Dimensions LxWxH | 7 x 7 x 2 inches |
| Item Weight | 0.01 ounces |
| Item model number | FBA_P-10-20521 |
| Manufacturer | ARRIS |
| Product Dimensions | 7 x 7 x 2 inches |
| Series | FBA_P-10-20521 |
F**L
Works Great; I'm not a Tech-Savvy Person
I bought this modem back in March 2020. It's now April 2022. We use a local cable internet provider (Service Electric). Our previous cable modem pooped out in March 2020. It probably caught COVID. Anyway, Service Electric told me I could buy a new modem with DOCSIS 3.0, and they recommended Arris brand. So, I bought this one. It arrived. I connected it. It worked. It still works. I don't know anything about internet speeds, up and down channeling, ping speed, etc., and I don't care. We are a homeschool family and use internet for things like email, online lessons, streaming videos, YouTube, podcasts, audiobooks, and paying bills. Our four kids don't have any screen devices. My husband and I don't let them touch our phones. We don't watch TV because we're old-school and do things like go on walks, read books out loud, eat meals together, play games, do chores, and do projects. We're also cheap, so we have a basic 25 mbps plan, or something low like that. Internet: When I type a web address into the address bar, the webpage comes right up. That's all I need. This modem never asks anything of me. When we lose power and the power returns, this modem turns right back on. This modem works constantly behind the scenes, never complaining, never asking for anything. It just keeps giving and giving, like Shel Silverstein's Giving Tree. Therefore, this modem gets 5 stars.
M**.
Great performance on Comcast (Blast tier)
It's not beautiful by any means but the performance more than makes up for it. Using it with Comcast Cable in March of 2016. The 802A is actually the retail model of this device and is on Comcast's approved equipment list while this 802 was meant to be distributed by cable providers and is not on the list. However, it will work and was easy to set up. When you call Comcast to activate the equipment just tell them it is the 802A and give them the seriel number on the device and Comcast will be none the wiser (it shouldn't matter anyway, but better to play it safe). Took about 10 minutes on the phone to get it activated. Provides stable performance and is better than the equipment Comcast provides these days. Buying your own modem will save you $10 a month on the equipment rental, paying for itself in just a few months. I have Blast speed from Comcast and actually get better than advertised speeds with this device (90 Mbps down and 15 Mbps up). Make sure you have your own wireless router if you want to set up a wireless home network, as this device is just a simple cable modem and not a cable modem/wireless gateway like the equipment you likely have from Comcast right now.
D**N
Careful, this is not covered under warranty by the manufacturer!
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.
A**X
This Modem Is Great! Awesome Deal
I have used this product for about Two weeks Already it is doing great and going fast. I did not give it five stars because this Modem WAS NOT NEW. It said "New" but it wasn't. Someone had already either set this thing up already or something. So when it got my house We had a bit of a struggle trying to get this thing to get on but it Was Eventually done! Wow The shipping was Very fast It was only like 2 days when it came and I did not use "Amazon Free Two day Shipping". It was working Fine now And I am enjoying my Internet Speeds!
C**.
Arris sent me an old refurbished modem with a different part no. I returned it because it was not what I ordered. I am a very unhappy customer. Waste of time.
Trustpilot
2 weeks ago
2 days ago