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RT AC86U CenturyLink 1GB GPON Speed issue

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Josh Lever

New Around Here
Hi all,

I have CL GPON fiber with the RT AC86U router connected to the ONT. I am connected using PPPoE & VLAN set to 201. I had a previous line speed of 100mb & was getting 100 up and down using a wireless connection.

I recently upgraded by line speed to 1GB, flashed Merlin 384.12, reset my modem and am unable to get close to the expected speeds. Currently getting ~200mb down (best case), upload is ~700-800mb. Adaptive QoS is disabled.

I've read stuff about Hardware/NAT acceleration and I think it's enabled, but not completely sure as i'm very inexperienced with this kind of stuff. Wondering if anybody could provide a list of settings for me to crosscheck once I can get back into the GUI?

Thanks in advance!
Go to Tools > Sysinfo and see if HW acceleration is enabled.
Thanks for the reply. Flow Cache and Runner are both enabled. Ethernet port WAN says 1Gbps, I also set my 2.4ghz to 20mhz (N only), and 5ghz to 20/40/80 (mix AC/N). Any other suggestions?

I was testing on DLSreports and again depending on the firmware version, couldn't consistently break 2-250mbs down. My highest upload was 850.

Additionally, when I look at the CPU cores, neither consistently exceeds 5%, usually hovers 0-3%. Would this indicate that the HW acceleration is not working despite the GUI saying it is enabled? I've tried the 4 most recent Merlin Firmware versions.
Last edited:
First of all, do not use QoS with a gigabit connection. Are you testing over wifi or wired?

Wireless mode should be set to auto. Turn off airtime fairness on both bands.

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