RyanJ09201's profile

New Poster

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10 Messages

Monday, September 20th, 2021 2:51 AM

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Wits end: trying to get actual, paid-for speed realized at PC using Xfinity 1.2Gbps Plan (Provisioned 1.44Gbps)

I am tired of researching and failing.

Comcast tech was out to the house and measured 1.3Gbps down to modem.

  • Link aggregation activated on Arris SB8200 modem
  • (2) CAT6 cables connecting both ports on SB8200 to WAN and LAN4 on Asus RT-AX86U router
  • WAN aggregation enabled and shows active on landing page of router
  • CAT6 cable from 2.5Gbps port on RT-AX86U to Plugable 2.5Gbps Ethernet Adapter (Model USBC-E2500)
  • Drivers updated from Realtek directly for RTL8156B
  • Plugable 2.5Gbps Ethernet Adapter plugged into USB-C on ASUS Z270E ROG Strix motherboard
  • USB-C port is confirmed running at “SuperSpeed” (3.1, 5 Gbps) using Windows USBView
  • Windows 11 on PC
  • Device Manager and Windows Task Manger returns Plugable/Realtek adapter is active and network connection confirmed at 2.5Gbps speed
  • All other network adapters (wireless and wired are disabled on client PC)

Ookla returns 450Mbps download speed: effectively half my known speed. Taking Plugable adapter out of equation, all other arrangements the same, except for plugging directly into built-in 1Gbps ethernet on-board, Ookla returns 850-950Mbps.

Someone, please HELP!!!

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Problem Solver

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948 Messages

4 years ago

Well on my realtek USB adapter it states on the Realtek website, if your using Microsoft plug and play drivers trying to get the fastest speeds, it says flat out it won’t happen, I used Realtek drivers with better results, I have the same router and used dual wan mode and get roughly 1500 Mbps, just a thought

(edited)

New Poster

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10 Messages

@jlavaseur 

Thank you for the reply. I installed the Realtek driver for RTL8156B from the Realtek website. I don't see a difference. Turning Jumbo frames on has improved the speed to about 800Mbps.

Just once, I would like to see the speed I pay for: something above 1Gbps.

New Poster

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10 Messages

4 years ago

What settings do you have in the Network controller advanced menu? Did you change any from default after installing the Realtek driver?

Also - when you say "Dual WAN" do you mean WAN aggregation or literally mean enabling dual WAN in the Dual WAN tab? If so, what settings? Do you have 2 IP or 2 ISPs?

Enabling Dual WAN in the RT-AX86U disables WAN Aggregation, so it's one or the other. I believe WAN aggregation is correct in my application with a single IP/ISP exceeding 1Gbps.

(edited)

Problem Solver

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948 Messages

4 years ago

Well you might have to experiment some, just do one at a time, then test, if your referring to the network work card in the device manager, personally i run a few different operating system on my one computer, Windows 10 was by far the worst to get it working correctly, when i boot to Linux, i got spectacular speeds right from the get go, so it told me there was nothing wrong with any of my hardware, on another note, i have a wifi 6 card in that same computer and it varies but i can get close to 1200 Mbps on a good day, also maybe try dual wan mode as i can verify i have gotten it to work, i have never tried WAN aggregation because dual wan mode worked right off the bat for me...

New Poster

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10 Messages

@jlavaseur Thanks again for the help - regarding dual WANs, do you have a single IP from Comcast, multiple IPs, or multiple ISPs?

I enabled Dual WAN, which disabled Link Aggregation. With the following settings, I was able to reach 935Mbps at both router and PC individually.

However, I now get an error on router's landing page:

(edited)

Problem Solver

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948 Messages

4 years ago

@RyanJ09201 I had only one ip from Comcast when I ran the dual mode setup, maybe your modem doesn’t support that I don’t know, I see it has two Ethernet ports, but I didn’t explore how they work

Problem Solver

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948 Messages

4 years ago

@RyanJ09201 I was reading on another forum, some guy was saying that the Usb C adapter, I guess it it can be inserted two ways, he said one way was slow, he flipped it and got the right speeds, I don’t have a C adapter so I don’t really know, worth a shot tho

New Poster

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10 Messages

@jlavaseur Thanks for the continued discussion. I think we can close this one: I found my problem.

The SB8200 modem, while capable of “10+ Gbps speeds”, this is a combined throughput across all clients. No single client will exceed 1Gbps - ever.

I have since switched to the Comcast/Xfinity XFi platform for unlimited data and am now using the XB7 gateway. XB7 Wifi is turned off since I am using my own ASUS RT-AX86U router to handle all the wireless clients. Wired clients are on a dedicated 5-port 2.5Gbps switch.

With my current setup, using the Plugable adapter, I was able to achieve a real-world, point of service Ookla speed of 1440Mbps (which is 1.2Gbps x 20% overprovisioning).

(edited)

New Poster

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14 Messages

@RyanJ09201 I just tried to use the Plugable adapter with my ASUS RT-AX86U and Motorola MB8611 modem and my speed was cut in half from the 950ish that I was getting before. I wonder if the adapter could be bad?

New Poster

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10 Messages

Is the *only* thing different between the 950Mbps and half of that is the insertion of the Plugable adapter. Are you on a 1.2Gbps plan? Have you updated the Plugable drivers using those on Realtek's website? Is the MB8611 properly provisioned an on the list at My Device Info (Using Approved Third-Party Equipment for Xfinity Internet and Xfinity Voice - Xfinity Support)?

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