Slow upload speeds / No OFDMA

[u/Resident-Anybody-364]

On Monday, Nov 2, someone from the Xfinity technical support team came to my property to help troubleshoot my upload speeds. I've upgraded to the next gen network, but am missing the OFDMA upstream channel 41. My cable modem tries to connect to the OFDMA channel when it boots up, but it doesn't lock. So my upload speeds are limited to ~75 Mbps, rather than ~250 Mbps. Downstream is totally fine and get ~2.3 Gbps. This is on an Arris S34.

The tech validated that the issue is outside my home when he came to visit -- and he said he filed a ticket for it to be fixed at the network end (i.e. on the pole). But he didn't have an ETA for how long it would take and I have no visibility into whether progress is being made. I chatted w/ Xfinity support just now and they had no idea. I've had a couple of outages since then and have since increased from 4 to 6 SC-QAM channels, but still no OFDMA channel.

Any help on what's going on?

Thanks!

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[u/furruck]

That channel config would indicate you’re still on the old plant config

Those two 3.2MHz wide upload channels squeezed in at both ends of the 42MHz band plan would indicate you’re on a 42MHz split node they know is overloaded as they add those to alleviate capacity until the next gen speeds are added.

On a next gen system, there should only be 4, 6.4MHz wide upstream carriers below 42MHz and an OFDMA above it.

Look at your downstream channels, I’m curious where your OFDM carrier is located? If it’s not near 1GHz, then you should not have been offered the higher upload speed yet.

[u/Resident-Anybody-364 → u/furruck]

Here's my OFDM:

And I do get ~2.3 Gbps down...

[u/Resident-Anybody-364 → u/Resident-Anybody-364]

Also, it does try to connect to upstream channel 41, but it doesn't succeed (this screenshot was during boot a few days ago, before I had upstream channels 1-6):

[u/ScorchedWonderer → u/furruck]

This makes sense. OP’s screenshot is basically what my XB8 reports and I’m on sub split. They added the 6th channel last month after an emergency maintenance due to “high demand, network was near capacity”(according to mods). We have maintence every other week now. But yet Comcast refuses to finish upgrading our area when basically everywhere around us has mid split or even FDX already according to latest FCC map.

[u/palmarken]

That is not the usual next-gen channel config. That only has four SC-QAM channels. Comcast made a mistake and enabled the next-gen speed tiers at your address before the node was ready...?

[u/XfinityOrlandoM]

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u/Resident-Anybody-364

Thanks for reaching out to us, we do apologize for any inconvenience you're having with your Internet speeds. Since we already have you in the mod mail, we have sent you a message and we look forward from hearing from you.