Review: Arris TM822G DOCSIS 3.0 8×4 Ultra-High Speed Telephony Cable Modem

Arris TM822 ReviewTo lease, or not to lease. That’s the question for anyone who gets their high speed Internet through Comcast Xfinity. Literally millions of Comcast customers (over 18MM, to be exact) are paying an extra $7 per month to rent a modem from the cable company, and if you’re unsure whether or not you’re one of them, then I’d be willing to bet you $7 that you are.

Admittedly, there are some benefits to coughing up the monthly $7 fee to Comcast. First, if your modem breaks, they’ll replace it for free. Second, if your modem becomes outdated, they’ll swap it our for an upgraded one for free. So, if those two benefits are worth $7 a month to you, then go ahead and keep on renting.

Me? I’m a cheapskate frugal. Thinking back on my cable modem ownership (and checking my Comcast account), it seems I’ve owned three cable modems over the past 12 years. My first was a Thompson RCA DCM 235 DOCSIS 1.0. The term “DOCSIS” is an acronym that stands for “Data Over Cable Service Interface Specification,” which simply refers to the type of technology used to send Internet “stuff” over cable TV lines. My original first-generation cable modem worked fine for years, but when Comcast started supporting the DOCSIS 2.0 technology on their network (which allowed for faster and more reliable Internet service), I upgraded my modem to a Linksys BEFCMU10 v4 to take advantage. I used the Linksys without issues until April 2012, when Comcast called to inform me that in order to take advantage of their most recent network upgrades, I’d need to upgrade to a newer DOCSIS 3.0 modem. That’s also when I decided to ditch my local telephone provider and switch my phones over to Comcast Voice, meaning I’d need to replace my cable modem anyway for one that supported telephone in addition to Internet. So, after reading some online reviews about the latest and greatest cable modems, and talking to some Comcast technicians, I purchased an Arris TM822G on Amazon for $59.95 (with free shipping and no tax).

Arris TM822G Cable and Telephony Modem

Arris TM822G Cable and Telephony Modem

Over the past 12 years, on average, I paid no more than $70 for each of the three cable modems I purchased. So if I take 12 months times $7 times 12 years, that equals $1,008 — and if I subtract $210 (3 modems times $70 each), that means I’ve saved close to $800 in modem rental fees over the past 12 years. And since each cable modem has paid for itself in less than a year, and none of them have ever broken before I’ve needed to upgrade them voluntarily, I still believe that purchasing your own modem is the right way to go.

I would have written a review on this modem back in April 2012, when I first bought it. However, I forgot one very important step when purchasing the TM822G:

I neglected to check Comcast’s Approved Devices List to verify that the TM822G was on the list.

In my defense, I never even imagined it wouldn’t be. Arris manufactures the modems that Comcast leases to its customers, so it never occurred to me that they wouldn’t support one of Arris’ most highly rated, fastest, and feature-rich modems — especially when a Comcast tech specifically recommended the TM822G to me as (and I quote) “the best.” But, to my dismay, the TM822G wasn’t supported by Comcast, so in order to switch over to their voice service last April (which saved me a bunch on my monthly phone bill), I was forced to pay the $7 monthly fee to rent an Arris TG862G instead, until they eventually got around to including the TM822G on their approved devices list. Finally, in September 2012, Comcast announced support for the TM822G, so I was able to return the rented modem and start using my own, which had been sitting… sad, lonely, unused, and unloved… in a box under my desk for months.

Without turning this post into a rant, suffice it to say that switching from the leased modem to my owned one didn’t go smoothly. It took two full days of constant phone calls and online chats with Comcast tech support, some posts in their support forum, and an in-person visit to a Comcast store, to finally get it all working properly. But, once all the wrinkles were ironed out, I was able to focus on an honest evaluation of the Arris’ TM822G modem without Comcast’s crappy customer service clouding the issue.

Quite simply, the TM822G is nothing more than a cable / EMTA (phone) modem. It’s not a wireless access point, it’s not a router, it’s not a gateway… which is exactly what I want in a cable modem. Keeping my wireless router and access points separate from my cable modem gives me far more flexibility over my network setup, especially since I use third-party firmware (such as DD-WRT and Tomato) on my WiFi routers and access points. And even though history has shown that I haven’t needed to do so often, having it separate also allows me to swap out the modem as necessary, without losing all the configuration options on my router. That’s exactly what I did when putting the TM822G into service. It took less than 5 minutes to physically disconnect the old modem and hook up the new one, without the need to take my internal network offline.

Speaking of connections, the Arris TM822G keeps things simple, with only five connections on the back: a power cable connector, an RJ-45 Ethernet port to connect to your router, a coax “F” connector to connect to the cable company, and two RJ-11 phone jacks to connect up to two telephone lines (technically, it’s actually one RJ-14 and one RJ-11). There’s also a reset button (which you’ll need a paper clip to press when the 14th Comcast support agent of the day asks you to press it, over… and over.. and over…)

The TM822G only has one available accessory: a backup battery to keep the modem (and your phone lines) running run the event of a power outage. I decided not to install it, however, for two reasons. First, I already plug all my network devices into a large battery backup unit, which only has to run long enough to wait for the generator to kick on. Second, I connect my modem, router, and main switch to that battery backup unit via a remote control Baytech power strip, which allows me to kill and restore power to any of those devices remotely — including via a Linux shell script that pings a number of sites to see whether everything’s working ok, and then automagically logs into the Baytech and reboots the modem and router if I’m offline (which fixes the issue more than 90% of the time).

Where the TM822G shines, as would be appreciated by former First Lady Eleanor Roosevelt, is “speed… hot, nasty, bad-a$$ speed.” It supports up to 8 bonded channels for downstream connections (providing for a theoretical max download speed of 343 Mbps), and 4 bonded channels for upstream connections (yielding a theoretical max upload speed of 122 Mbps). In actuality, with Comcast’s top tier of residential service, I get around 35 Mbps down, and 5 Mbps up. UPDATE! Comcast upped their speed for my service tier in April 2013, so now I’m getting just under 50 MBps down and almost 12 Mbps up:

That’s at least 10 25 Mbps more “down” than I was getting with my old DOCSIS 2.0 modem, and a couple more double the speed “up,” to boot. That’s still comfortably within the expansive capabilities of the TM822G, so if (when?) Comcast eventually decides to cough up more bandwidth (like they did in April), the TM822G will be able to handle it.

In addition to raw speed, the TM822G also shines when it comes to specifications compliance. It supports IPv6, PacketCable 1.0 and 1.5, SIP (according to RFC2161), encoded speech codecs G.711, G.726, G.728, and G.729E, and has T.38 fax relay support. If all that makes your eyes glaze over, just take my word that the TM822G has all the “goodies” to ensure that it won’t be outdated anytime soon (you can check the spec sheet for more geeky awesomeness). And to get all that for $59.95 is a steal.

Which brings me to the only bad news of this review:

You can’t buy an Arris TM822G for $59.95 any more.

I suppose it’s the law of supply and demand. When the TM822G wasn’t supported by Comcast, there was little demand, meaning retailers had to sell them for cheap if they wanted to sell them at all. But now that it is on Comcast’s list, and given that it’s the fastest, most highly rated, and one of the most reliable cable modems in a number of independent tests, the Amazon price is now closer to $190 and the eBay price is around $160. Even used, they’re going for between $80-$100 on eBay.

Warning: if you decide to buy one used, be very careful. If it was already provisioned (or set up) on the Comcast network by another customer, I’ve read horror stories online about trying to get them re-provisioned for your account.

Of course, this price jump isn’t Arris’ fault, but it does extend the break-even point for your $7 per month potential savings, which is something to keep in mind as you make that decision.

My decision is easy. At the price I paid for it back in April, and even at the price you’d probably have to pay for it today, this cable modem is a winner. So if you’re ready to stop coughing up $7 a month to Cabletown Comcast, the Arris TM822G is almost certainly going to last more than long enough to get you to a break even point.

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  1. I wish I had NEVER gotten this Arris TM822G Modem. As soon as the tech installed it I lost my e-mail.I called Comcast for help again and again with NO results. Comcast help is Terrible. Then a supervisor came out and tried to get Comcast to fix my lost e-mail. He also had no luck. The loss of e-mail (I use Microsoft Outlook 2003) is not worth the unnoticeable increase in speed and the higher price.

    • My daughter had a similar problem. Sometimes Comcast assigns a new email to your account when you get this telephony modem. Ask them what the primary email is on your account. If this does not help, sorry.