FiOS gigabit service: Down: 800-900mbps, uplink capped at 325mbps

[jpiszcz]

Currently on Verizon's Gigabit FiOS plan, after it was installed I was seeing symmetrical ~900/840mbps over ca6a/ethernet using speedtest.net, everything was great! Yesterday, I noticed upload speeds seemed to be capped at 325mbps, download is normal at 800-900mbps.

Using Verizon's speed test tool it sees ~944/894mbps and FiOS support says there is nothing wrong with their network.

Using any other speedtest tool besides Verizon's, all report the same issue for the uplink (downlink is fine):
- speedtest.net - 930mbps down, 217 mbps up
- speedtest.net #2 - 874mbps down, 88 mbps up
- google speedtest - 873mbps down, 51 mbps up
- fast speedtest - 960mbps down, 260 mbps up

Using Verizon's own speedtest tool shows normal performance, after Verizon ran this test, they said there is no issue with the service and there is nothing they can do to fix the problem.
»www.verizon.com/speedtest/
- verizon.com - 944mbps down, 894 mbps up

Has anyone run into something like this before and how did you go about troubleshooting it with Verizon?

[kh-taylarie]

Hi jpiszcz,

Your issue has been escalated to a Verizon agent. Please check
your Private Messenger Inbox for a message from a Verizon Support agent. You can find
your Inbox by clicking on the envelope icon next to your avatar at the top right corner of
this page. Response times may vary. Please continue to check your Inbox for a reply
from a Verizon agent. Please direct all correspondence concerning your issue to the
agents who will be assisting you privately.

[jpiszcz]

Good morning kh-taylarie, thank you for your quick response, I checked my private messages and the last private message I had received was from 05-12-2021 04:41 AM. I will continue to check thank you.

[jpiszcz · Accepted solution]

Hello,

Details:
Incase anyone else runs into this issue, the way Verizon asked me to troubleshoot was, remove the Verizon router from the equation, so the ONT ethernet cable runs to a wall-jack and then directly to my laptop.

Testing to the ONT directly:
I saw normal speeds consistently via speedtest.net, 941mbps/946mbps.

Router setup:
After I finished testing to the ONT directly, I re-attached the ethernet cable from the ONT to the Verizon White Router (CR1000A) and I am now seeing normal speeds again. If the issue persists I will remove the Verizon router and see if the issue recurs again when it is not in use.

Hopefully these troubleshooting steps can help someone in the future to troubleshoot a similar issue.

Thanks all,

Justin