U

Monday, November 27th, 2023 5:22 PM

Customer Owned Modem MB8611 works with 1200mbps, but not 2000mbps

I have a Customer Owned Modem MB8611 which works with 1200mbps, but not 2000mbps. Looks like Xfinity just released the 2000mbps speeds to work with customer owned Modems, previously it required the xFi Gateway. I was told by Comcast that my Motorola MB8611 was compatible with the 2000mbps Plan. I have been using my MB8611 on the 1200mbps Plan without any issues for several months now and the day after I upgraded to 2000mbps and my Modem reset, it would not go back online. It just cycled through the boot sequence and kept dropping packets when establishing Internet Connection. I was without Internet for 2 weeks and had 3 Onsite Techs come to my house, as well as multiple phone calls/chat messages, to try and figure out what was going on. The first Tech said it was a Hardware Issue(It wasn't...), but I bought a brand new Modem of the same model to eliminate that possibility. The Second Tech that came to my house determined that there was issues with the Terminal outside of my house and that everything within my house was working properly, including the Modem. A Lines Men/Field Tech came to work on the Terminal and stated they fixed the issue. However, the problem still persisted even have Factory Reset and unprovision/reprovision. I ended up downgrading my service back to 1200mbps and had the 3rd onsite tech reprovision my modem in order to get it to work with 1200mbps again.

Can anyone confirm if there is a Firmware/Compatibility Issue with Xfinity's 2000mbps plan and the MB8611? I am assuming since this was just recently released for Customer Owned Modems, there are still bugs being worked out with the SW ver.

Accepted Solution

Expert

 • 

102.9K Messages

3 months ago

AFAIK. These are currently the only third party / customer owned devices that are compatible with the next-gen speeds. 

(edited)

3 Messages

Well that explains a lot...Not once was this brought to my attention by any of the support reps I talked to live or in person. Also, in reference to your screenshot, I think they mean the CM2000, the CM3000 doesn't exist. I guess I will just wait for the MB8611 to become Next Gen Speed Tier Compatible. 

9 Messages

Per Xfinity's list of supported modems, the MB8611 is not longer a "Recommended" modem. As I recall, it was on their recommended list when I bought mine back in April 2022. Thought, I'm not sure why as the modem itself is DOCSIS 3.1, and Motorola itself says it's capable of upload speeds up to 800Mbps. It is really frustrating to constantly have to upgrade modems every 18 months because Xfinity is locking them out.

list: https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2023.11.22%20Full%20List%20of%20Compatible%20Devices.pdf

Expert

 • 

102.9K Messages

3 months ago

Although I am not certain, the 8611 may never be able to become compatible. A firmware update alone may not be enough if the hardware itself lacks the proper circuitry.

9 Messages

3 months ago

I just had the same experience last night. I've been using an MB8611 since mid-2022, and it's been solid. I was on the 1200/200 plan, and was getting speeds of ~1.3Gpbs down and ~40Mbps up. Which makes sense given the limits are usually 20%-ish over the stated plan numbers. I called Xfinity support asking why I wasn't seeing the 200Mbps upload speeds, since that's the plan I'm on, and I know the Mid-split upgrades have been rolled out through (all, most?) of the Atlanta market. I kept asking if they could tell me if the Mid-split had indeed been rolled out to my neighborhood/address - they didn't seem to know what I was talking about. I tried asking if the problem was that my modem was being "blocked" from the higher upload speeds, because per specs, it's capable of something like 2300/800. Again, they didn't seem to know what to make of this question.

They said I needed to be on the 2000/200 plan to get the 200Mbps up, and it would be just $8/mo more. I tried to explain that doesn't make sense, but went ahead and allowed them to upgrade. The modem rebooted and then spent 30 minutes trying to get online. I restarted it. Factory reset it. All of the usual tricks. Then I called support back. Another hour later, and them trying all of the "we're sending a refresh," etc… and it still wasn't online. They wanted to send a tech out - in 3 days - to have a look. So I had them move me back to the 1200/200 plan. The modem restarted and immediately re-connected. Speed tests showed I was again getting ~1.3Gbps/40Mbps.

At this point, I'm pretty sure it's Xfinity "blocking" my modem from getting the higher speeds. I've ordered a CODA56 modem, which is on their Next Gen Speed Tier list (as seen in @EG post in this thread). It arrives Sunday. The same day a tech is supposed to come out and test everything.

9 Messages

3 months ago

UPDATE: The new CODA56 Modem came in a day early. I hooked it up, used the Xfinity app (over 5G) to activate it, and after a couple of reboots it was online. I ran a speed test from my router (UniFi Dream Machine SE) and it pulled 1.3Gbps down and 236Mbps up. I'm still on the 1200/200 plan, so with the typical ~20% over-provisioning, those numbers seem right. It seems Xfinity is blocking the MB8611 from getting the faster upload speeds.

Official Employee

 • 

1.2K Messages

I'm glad to hear the modem is working well, and you are getting the right speed, @harmanly. That's awesome! Thanks for the update! 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Expert

 • 

102.9K Messages

3 months ago

Thanks for that feedback @harmanly ! Wonder how the original poster @user_clbzs4 is making out ?

forum icon

New to the Community?

Start Here