docsis 3.1 - not seeing greater than 40mpbs UPLOAD

You’re not going to see an increase in upload speed if you’re not on xfi complete and using a xb7 or xb8 modem.

Secondly you don’t need docsis 4.0 to go over 1 gig as 3.1 can handle that just fine. You can’t even get docsis 4.0 as it hasn’t officially been released and is still in testing.

Lastly if your plan works fine for you ignore what Xfinity is telling you. They’re a company that is always trying to make money. They use a lot of fancy marketing jargon to try to get you to upgrade. That’s all. 

so I guess since i'm using my own modem, xfinity would throttle me down on my upload? that doesn't make sense and [Edited: Lunuage]. the whole point of me sticking with comcast for quite some time is i can use my own equipment so i don't have to rent, plus there's some configuration i like with my wireless router (mesh network) , ethernet backhaul, vpn, etc. i mean i've lived with it for so long with 40mpbs but would sure be nice i can get more than that. (hope you're listening there comcast!)

Same here! Exact sa.e issue on the same plan on Docsys 3.1 Motorolla modem

Same issue with Arris 8200 modem with same plan 

Go into your modem GUI and check to see if any Upstream ODFMA channels are locked, if not; the high upload speed upgrades havent been completed yet for your market.  If one is locked, then your market is close to being completed....

So is this ever going to be supported or are they going to try to force us to use all of their bloated hardware?  This is extremely anti-consumer.

Comcast, please advise.  

Update and for crying out loud, I have to download and use a new browser (Brave) since Edge, Chrome and Firefox have the description all greyed out. Oddly enough and not long after talking to customer service about my internet only contract, savvy agent confirmed that Xfi is the only way to get my contractual speeds of 1200 down / 200 up. But there would be possibilities of being able to use my own equipment to get that speed maybe next year. 

Maybe next year was meant as around the corner because not even 1 week after the call, I get the email about updated compatible device I can use to get faster upload speeds than 40mpbs. I bought and installed the CODA56 and tested it direct connect to my desktop pc using a 2.5gb  port. I was getting very close to those speeds. My router is now my limiting factor for 1 pc since it I can't break past 920-950mpbs via my router that is gigabit only. But direct connect with a 2.5gb port from desktop? i'm getting > 1gb speed. At least even if the router is limiting, I'm getting almost a little over 4x the upload speed with the CODA56 modem. 

Exact same issue here guys. I received an email a couple days ago from Xfinity telling me that I need to upgrade my modem to take advantage of new 5x-10x speeds on the upload side. There were 5 modems listed in the email with no reference or link to a larger list of compatible modems. Strange that there's only 5 cable modems out there that can handle more than 40mbps upload speed, right? haha 

Here's the steps that I took before I gave up:

• I first called Xfinity and confirmed that my modem is actually compatible with Xfinity (which I already knew was a "yes") and was capable of the higher speeds (which I also already knew was a yes since it's a DOCSIS 3.1 modem). 
• Xfinity ran some tests remotely and confirmed that everything "looks good" from their side. Didn't give me any further details what they were actually doing. 
• Xfinity sent out a technician and he was able to confirm speeds coming into the house are reaching the advertised levels (~1200mbps download and ~200mbps upload). Technician was also able to confirm that the speeds coming out of my modem were downgraded to somewhere around 900mbps download and 40mbps upload, confirming that the issue is at the modem. Technician wrote up the visit as "customer equipment at fault" and told me to call the modem manufacturer.
• So I followed the advice and called the modem company (Arris) and went through their 30-minute troubleshooting process. In the end, they were able to confirm that everything looked good on the "Downstream channels", however, "Upstream channels" coming to my modem were below the required power range. I was somewhere around 42/43 dBmV whereas Arris told me the range must be between 45-61 to avoid any intermittency with connection or slower speeds. I asked if this was really enough to cause this downgrade in speeds and they assured me that this was the “smoking gun”. 
• Called up Xfinity and ran through what I had learned from Arris and they immediately scheduled an "escalation appointment" with a technician same day to come address the issue. 
• During the escalation appointment, the technician confirmed that my “Upstream channels” were below Arris’s spec, but did note that they were still within Xfinity’s spec (there appears to be a misalignment between Arris and Xfinity on what is considered “in-spec” for “Upstream Channel” power). By adding a splitter to the cable line prior to my modem, he was able to bump up the power to just above 45 dBmV to get it within Arris’s spec. After running a new speed test directly connected to the cable line and then directly connected to my modem, the tech was able again to confirm that speeds coming into the house were exceeding 200mbps on upload but speeds coming out of my modem were still in the range of 30-40mbps. So now I know that Arris’s “smoking gun” was not correct. 
• Next step, I called Arris customer support back and explained that an Xfinity technician had recalibrated the upstream power going into the modem to be within their spec (as they had requested) and yet we are still experiencing throttling of speeds coming out of the modem. Arris went through a 45-minute troubleshooting session and concluded that the issue “appears to be with the device itself” and offered to do a warranty replacement. However, the advanced replacement warranty requires me to pay for shipping ($20). Their other option is for me to unplug and mail them my modem and wait for a replacement - what a joke to think that a customer can just unplug their modem and go offline until they send a new one. Since it seems to me that Arris has no idea what the issue actually is and I’ve seen this thread with multiple other people experiencing the same thing, I am thinking a replacement modem is not going to result in anything here, so I am opting to give up at this point. 

Not being an expert here at all, I feel like somehow Xfinity is somehow only unlocking the higher upload speeds for customer-owned modems listed in their email they sent me. Guessing they get some sort of kick-back from the sale of those modems. Seems like another case of Xfinity trying to deceive their customers into thinking they are giving us something for free out of the goodness of their heart haha