D

6 Messages

Friday, January 10th, 2025 1:32 AM

Just upgraded to an Arris S34, but still only getting 40 Mbps upload speed

I recently upgraded to the 2gbps/300mbps plan that became available in my area but was still getting slow upload speeds, so I just upgraded to the Arris S34 cable modem after seeing it on a list showing that it supports the next gen upload speeds (here).

My speed tests directly from my Ubiquiti Dream Machine Pro, wired from a 1/2.5/10GB SFP+ over Cat 6A ethernet, shows download speeds around 2.33 Gbps, but my upload speeds are still only hitting 40 Mbps. Is there something on the back end that needs to be configured for it to upload properly?

Accepted Solution

6 Messages

2 months ago

My new modem was added but wasn't marked as the Active modem, so it was still limiting the upload speed to 40mbps. Support was able to fix it by setting it to the active one and restarting the modem.

Official Employee

 • 

1.6K Messages

@drakkan Thank you for sharing the resolution here with our community. Have a nice rest of your day!

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

2 Messages

How do I get my modem marked as active? I have this exact issue, and I had Xfinity come out and check my service. It reports 1.9Gbps and 400mpbs up. However, when I connect the modem, it returns 40, almost perfectly the same. 41.00Mpbs. I have gotten no answers on a solution to this for months now.

Official Employee

 • 

1.2K Messages

2 months ago

Hi there, @drakkan! Thanks for reaching out to us here on the Community Forum! Would you be able to try a test directly from the S34 to a desktop/laptop, without the additional networking equipment to see what speeds you get? Reason being, if you're getting the correct download speed then it is likely we are already configured with the correct bootfile. The true test of speed is going to be a direct connect via ethernet to one laptop/desktop. Let us know the result when you get a chance to try that. Thanks! 

6 Messages

Why would that help if I'm already testing from a device directly connected to the modem? It's a very expensive enterprise network appliance that will outperform any of my computers in network performance. It has two 10Gbps ports on it, one of those is connected directly to the modem.

Official Employee

 • 

2.4K Messages

Thanks for the clarification! Since you're already testing with a high-performance enterprise-grade device directly connected to the modem via a 10Gbps port, we can rule out local equipment limitations.

To move forward, we’ll want to check a few things:

  • Confirm the modem’s bootfile is properly provisioned for your speed tier.
  • Verify signal levels and ensure there are no issues with the line quality.
  • Run diagnostics on our end to identify any possible provisioning concerns.

Our awesome digital care team would be happy to assist you. Can you initiate a direct message and start with your full name and address? To start a direct message, you must be signed in. Please click the "Direct Messaging" icon in the top right of the page next to the bell, and send your message to "Xfinity Support". Talk to you there!

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Visitor

 • 

2 Messages

What values should these be set to for optimal performance?

  • Confirm the modem’s bootfile is properly provisioned for your speed tier.
  • Verify signal levels and ensure there are no issues with the line quality.

Visitor

 • 

2 Messages

2 months ago

Same question.  I just upgraded to the Arris Surfboard S34, based on the recommended list provided on XFINITY's website (https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2024.09.18%20Full%20List%20of%20Compatible%20Devices.pdf)

I am limited to 40mbps upload speeds.  I am using a CAT 6 cable directly from the S34 to my laptop.  Download speeds as expected for my 2gpbs tier.  But upload speeds are nowhere near where I am paying for.

What do I need to change or do to achieve those upload speeds?

9 Messages

12 days ago

WOW, I WISH I could get those download speeds.

We just "upgraded" from the gig-extra 1200 plan to the gigx2 2000 speed plan. NOTHING but problems since the swap.

I previously was using their XB8 modem/router with very few issues at all and I used to be able to get over 1200 download on the old plan. Then right after the switch we were only getting around 800 right next to the XB8 and the wifi range got cut in about half too even though their app said their XB8 was receiving over 2000.

MULTIPLE trouble shooting efforts, 3 different XB8's, multiple chat and phone techs, and even techs to the house and NOBODY can even figure out what is wrong MUCH LESS fix my internet and wifi issues.

I finally got so sick of dealing with the XB8 that I completely got rid of their dumb XB8 modem/router and got my own ARRIS S34 modem and a Deco BE65 PRO router mesh system.

STILL do not get anywhere near 2000 download speeds. Barely getting over the 1200 I could get on the old plan and that's only if I'm connected to the Deco BE65 directly with my cat8 ethernet cable. EVEN though the Deco app says it is receiving around 1.8-2.1 from the modem depending on when I test it.

What is even more weird is that if I connect to the MAIN Deco(connected directly to the ARRIS S34 with cat8 ethernet) with my laptop via ethernet I can get about 1600-1800(even though the app still says its receiving higher than that), BUT if I skip the router completely and go connect directly to the ARRIS S34 modem with the laptop and the same ethernet cable I am only getting 300ish down! makes no sense at all!

I am actually getting the 300+ upload speeds but download is trash ever since the internet plan switch.

I am now paying xfinity for up to 2100 down and yet still only getting what I was on the 1200 plan.

I thought the ARRIS S34 might solve my problem but it has not, and now it presents an issue of its own with that connection issue being MUCH slower than the one at the router.

I have run out of ideas on how to fix it.

Official Employee

 • 

1.3K Messages

Krk34 thank you for using the Xfinity Community Forums page to reach out regarding your upload speed concerns. I know how important it is to get the speeds you pay for and anticipate and would be happy to take a closer look into what is causing this issue for you. Please send me a direct message with your full name and complete service address to take a closer look into things on our end. 

Here's the detailed steps to direct message us:
• Click "Sign In" if necessary
• Click the "Direct Messaging" icon (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message. 
 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
forum icon

New to the Community?

Start Here