SB8200 Firmware Update or Replace

  • 20 January 2023
  • 9 replies


I was on wih Xfinity tech support today because for quite a while I am not getting anywhere near my availble speed which should be around 1 GB. I get anywhere from 300-600 Mbs.  They are telling me i need to update the firmware on my modem. Its not even 2 ½ years old and I bought this model specificially to meet my needs for gigibit speeds. Additiaonlly there doesnt seem to be an available firmware update. So my questions are;

1. should I need to update firmware for a device that should already have gig speed?

2. Is xfinity blowing smoke?

3. Is there firware available that I am not seeing?




Best answer by Netopia 20 January 2023, 06:22

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9 replies

Userlevel 3
Badge +23

There might be miscommunication between you and Xfinity support or you got someone who doesn’t know what they’re talking about. 

1. The modems software can only be updated by cable providers.  This is per DOCSIS standard.  Users cannot update softwares on cable modems.  Maybe they meant to tell you to upgrade the firmware in your router. 
2. If you have 1Gbps service, I don’t think Xfinity  allows the SB8200 on their gigabit service. At least not in my area.  You can check on


Userlevel 6
Badge +40

I’ve used the sb8200 on gigabit. It does work. The problem is that xfinity’s gigabit plan is 1.2gis so they say it isn’t supported because the sb8200 only has gigabit ports. But it does work. 

Did you test your speeds with a pc/laptop directly connected to the sb8200? Disconnect everything from the modem and reboot it. Then connect a pc/laptop to it and test its speeds. See what you get and post it here. 

Userlevel 3
Badge +23

@plemans The SB8200 will work on your gigabit plan but will operate on the next highest speed plan (800 Mbps).  I had to upgrade to S33 since upgraded to 1 Gbps service.


So when I originally bought the SB8200 it was supported at the time and it worked fine, now it says its not, so that pretty frustrating. I didnt even think that would have been the issue. I am in new place from when I originally bought it and was in fact getting higher speeds then I was paying for at my old place because I was so close to their hub. I think I had like a 400 meg plan and was getting almost double at times.

I had done several direct connections and yesterday my max speed was around 650 megs.

Looks like I am buying a new modem. 

Thanks for you help.


@plemans The SB8200 will work on your gigabit plan but will operate on the next highest speed plan (800 Mbps).  I had to upgrade to S33 since upgraded to 1 Gbps service.

Im not sure I follow.  What is the the S33 upgrade? Is that a new version of the SB8200? Im feeling pretty idiotic. I havent had to mess with modems quite some much since the 56k days. LOL.

I am aware that it “should” support gigabit and it has in the past. I cuurently have a 1000 Mbps plan with Xfinity, but since buying my house I have never reached that speed or even close. Additionally the site says it not compatable (when i originally bought it was).


Userlevel 3
Badge +23


The S33 is the latest D3.1 modem ARRIS offers.  It support multi-gig service and has 2.5 Gbps Ethernet port.


Next thing I need is a Wi-Fi router with 2.5 Gbps port on the WAN/Internet side if when I upgrade to 1.2 Gig or 2 Gig service.


This is my first day and first time in the community.  However, I have a similar issue.  I have a S33 and 1Gig service.  I recently checked and found my speed was around 380mbps.  Previously, when I had this problem, I called WOW and complained.  My speed would go up to around 800mbps sometime even to 900mbps.  As of two days ago I was told, after WOW sent a tech that my levels were low and they would be fixed.  After waiting for a day, there was no change in speed.  Called again.  Now I’m being told the levels are correct and it must be my modem and I should check for a firmware update.  I’ve agreed to try their modem ($14+/month) for one month to see if there is a change.  Oh, I was told their modem would be an Arris.  When asked which model, the reply was “a DOCSIS something”.  

   Later today they are to deliver their modem.  I plan to troubleshoot my S33 and note the levels in the downstream and upstream channels.  I’ll compare the levels with info in the Arris Consumer Care FAQ ‘S33: Troubleshooting Internet Connection” before I do a “self-install” of their modem.  Afterward, I’ll check levels in their modem.  

     More later


I forgot to mention:  I was connected directly to the modem with my computer when running the speed tests using the WOW web speed test app.

I checked all my modem signal levels and they were within range.   Did several speed tests and my speed was much better.  My highest speed was 946.90 Mbps., with an average of 943 Mbps. I guess the ISP started providing the 1 Gig service, I should have had.   I cancelled the appointment to receive the ISP modem to use.  My S33 is great!  Just needed the ISP to provide the service.