Arris S34, OFDMA upstream channel not provisioning for next-gen upload

It seems my new Arris S34 isn't being being provisioned with the latest firmware and/or boot file needed to take advantage of the OFDMA upstream bonded channel necessary for next-gen upload speeds. This is a problem related to slow S34 upload speeds that I'm seeing in the forums here and elsewhere. My experience lines up with the others.

I upgraded from an S33 to an S34 after upgrading my service tier from Gigabit+ to GigabitX2 (2000/300 speeds) earlier this week.

My current Arris S34 firmware version is AT01.01.010.042324_S3.04.735

I'm testing speeds using a wired network that's 2.5gbps from the modem to a 2.5gbps firewall (OPNsense), to a 2.5gbps managed switch, to a 2.5gbps integrated NIC on my motherboard.

Speed tests from several services show I'm downloading at up to 2030mbps, but my uploads never go higher than 85mbps. I'll see an initial burst to around 85mbps but then is settles to 70-80mbps.

When booting my modem and signing into its web GUI as soon as it's available, I briefly see what should be the OFDMA channel appear with the status "Unlocked" (instead of "Locked") and channel type "Unknown" (instead of OFDMA). While is says "Unknown", it does show the expected OFDMA frequency of 36200000 Hz and width of 44400000.

After a moment of the modem being back online (web browsing working on devices), the "Unknown" channel disappears suggesting it was unable to be established with Xfinity.

I've worked my way through web chat support, tier 1 phone support, and then a supervisor. All were very kind and helpful but unable to resolve the issue. If there's someone from higher levels of Xfinity tech support or engineering familiar with this issue that can resolve this, I'd be grateful for your help.

Here's one helpful related post for reference:

https://www.reddit.com/r/Comcast_Xfinity/comments/1fkay76/arris_s34_is_finally_working_for_nextgen_fast/

tl;dr: "It seems I was not getting the correct boot file when my modem restarted, but a "special code" can help force the right boot file to be sent. Here is a quote from the support rep: "I have a code that I can add to try and force the correct bootfile to come through. We add that in our billing system but it doesn't change any details of your plan or pricing. This will cause the modem to provision again and reset. This should get the faster speed coming through when you are back online.""

After this, the forum user's uploads were performing at next-gen speeds. They also reported having disconnected their firewall/router from the modem to avoid any conflicts during provisioning but weren't sure if it had any impact. I've tried disconnecting my firewall alongside a regular reboot, but not coordinated with Xfinity pushing a reboot / re-provisioning the modem.

Responses

XfinityJorge

Official Employee

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2.1K Messages

5 months ago

eentfgcnptecdko Thank you so much for using our Forums and we are sorry to hear about the issues you are having with not getting the speeds you need. Our team is happy to help and we appreciate all the details you have provided to us. Please send us a DM with your name and address to work together. Here's the detailed steps to direct message us:
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• Click the "Direct Message" icon (upper right corner of this page)
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user_5do7r9

2 Messages

1 month ago

Hello, any idea how this was fixed? I currently have the same issue.

eentfgcnptecdko

2 Messages

It never got fixed, although to be fair, it's not Xfinity's fault. An Xfinity technician came out to my place and determined the coax wiring in my 35-year-old apartment was as old as the building and allegedly it's a thinner gauge that has difficulty carrying the signal frequency needed specifically for the next-gen upload speeds. I'm not sure if I completely buy that it's the coax itself (2 gigabit down works great but 300 up doesn't?) , but I was satisfied with all the troubleshooting and ruling other causes out that the tech did while they were here. It's definitely something with the wiring in my building, one way or another.

1 month ago

hold_my_beer

5 Messages

I too am having the same issue.

1 month ago

user_knjx22

Visitor

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9 Messages

1 month ago

I had/have exactly the same problem. Mine is intermittent though.

Same S34 Modem, and when the OFDMA locks i get 330 Mbps up. If that OFDMA is missing then it caps at 80 Mbps up. My down is consistently above 2000 Mbps down in any case.

user_knjx22

Visitor

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9 Messages

Also, related to my post. The tech came out and used his field modem to measure down/up speed and he confirmed the full down 2000 and up 300 was there. That means I don't have a signal problem. The modem either gets a bootfile that doesnt work Or there is some sort of device compatibilty problem with Arris S34 and Xfinity. Again, my upstream speed issue is intermittent and isolated to OFDMA upstream channel not always locking on modem reboot.

1 month ago

XfinityDena

Official Employee

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3.2K Messages

@user_knjx22 I am sorry to hear you are still having issues with your services. Have you looked into a new modem or reached out to the manufacture for additional assistance?

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28 days ago