. Speed Test CenturyLink

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Internet Speed Test

Getting the Internet speeds you are expectng is important. This section will give you the tools needed to improve your experience.

Before The Test

Close Apps

Close everything such as Pandora, Netflix, Hulu, Spotify, all browser windows and any other programs that stream video and music. If it uses the Internet, you'll want to shut it down before you run the test

Connect Direct

Connect your computer directly to your modem. Testing should be done with a single device connected directly to your modem using an Ethernet connection. Also remove any hubs, switches or routers between your computer and the modem.

Other Devices

Turn off or unplug other computers, web-enabled printers and TVs, other routers, tablets, smart phones, web cams, DVRs, game systems, VoIP phones and content streaming devices such as Roku, Apple TV, and Chromecast.
The Speed Test

  • If you get a flash error, trying using the HTML 5 version of the speed test.
  • If you are using https, remove https from your address bar and try again.
  • If you are using a mobile device and you want to test your CenturyLink Internet service, enable Wi-Fi and connect to your CenturyLink wireless network. Make sure you are NOT using a wireless data connection such as 3G, 4G, or LTE.
  • Using a Virtual Private Network (VPN) may result in test errors or slower results than expected. Try disconnecting from the VPN and re-running the test.
After The Test

Not what you expected? The speed test is a snapshot of your service at any given point in time. You may want to re-run the test a few times in a row to see how the results improve. If you're still not getting the speeds you expected, here are a few things you can try.

For wired (Ethernet) connections

Doing a little troubleshooting and trying the speed test again sometimes helps.

For wireless (Wi-Fi) connections

While wireless Internet speeds won't be as fast as wired Internet speeds, here are some resources to help improve your WiFi connection:
What is overhead, and how does it affect bandwidth?
  • The information you send/receive over the internet is broken into packets. Overhead allows the routing, error correction, assembly/disassembly of the packet. Without overhead, your information wouldn't know where to go, be able to reassemble at its destination, or repair itself when corrupted.
  • There are a lot of factors to consider when figuring out how much overhead is affecting your bandwidth. These factors include the physical connection (wired vs. wireless), the protocol (TCP vs UDP), IP version (4 vs 6), duplex settings, packet loss and retries, and security protocols.
  • With HTTP for instance, a large number of headers, large cookie values, multiple cookies and the like can consume 25% of your bandwidth. - http://packetpushers.net
  • Wi-Fi adds more overhead, which reduces your usable bandwidth even more.
Compare your results to the table below. The 'target speed' is 80% of your 'download/upload speed'. This is because 20% of the speed is used for protocol overhead. Testing should be done with 1 device connected directly to your modem using an Ethernet connection. All other devices should be disconnected and powered off during testing. Want to learn more, check out other factors that can slow down your Internet.

Download* Overhead Target^
1.5 Mbps -20% 1.2 Mbps
3 Mbps -20% 2.4 Mbps
4 Mbps -20% 3.2 Mbps
5 Mbps -20% 4 Mbps
6 Mbps -20% 4.8 Mbps
7 Mbps -20% 5.6 Mbps
10 Mbps -20% 8 Mbps
12 Mbps -20% 9.6 Mbps
20 Mbps -20% 16 Mbps
40 Mbps -20% 32 Mbps
1 Gig -20% 800 Mbps
Upload* Overhead Target^
896 kbps-20% 716 kbps
3 Mbps -20% 2.4 Mbps
5 Mbps -20% 4 Mbps
20 Mbps -20% 16 Mbps
* Not all speeds are available in all areas.

^ Tests run over a Wi-Fi connection may not represent your full broadband connection speeds. Learn about factors that can affect your Wi-Fi connection speeds.
Windows 10: factors that can slow you down

If you have Windows 10 connected to your network, it could be slowing you down.

Windows 10 has a feature known as Windows Update Delivery Optimization (WUDO). This feature was designed to help users get their software updates quicker, by using peer-to-peer sharing. This setting, when enabled, uses your Windows 10 computer to provide other Windows 10 users a portion of their download (like a bittorrent service).

The result, your Internet slows down while updates are being "shared" across the internet to other Windows 10 users.

How do you turn off Windows Update Delivery Optimization (WUDO)?
  • Go to "Start"
  • Select "Settings"
  • Select "Update & security"
  • Select "Windows Update"
  • Select "Advanced options"
  • Select "Choose how updates are delivered"
  • Under the section "Updates from more than one place", turn the toggle to the "Off" position.

If you can't connect to the Internet on Windows 10, check out this WINSOCK issue.

All Users: factors that can slow you down
What is Ping, Jitter, Download, and Upload?
  • Ping is a good tool to see if another host is reachable and if there are delays. Ping times do not test Speed (Bandwidth). If you have high Ping times, check your setup!
  • Jitter tests the performance and speed of a network over a period of time. If you have high Jitter times, check your setup!
  • Download is how fast you can pull data from the server to you. Downloading is necessary for things like streaming movies or TV using services like CenturyLink Stream.
  • Upload is how fast you send data to others. Uploading is necessary for things like sending big files, video-chat, or posting pictures to facebook.
  • Speed (Bandwidth) vs. Latency
    Latency is how long it takes data to travel between its source and destination.
    Speed (Bandwidth) is how much data can travel between its source and destination.
Running a speedtest over 1 Gig.
With speed this fast, you need to make sure your equipment can handle the speeds.

Quickly identify and fix issues. Determine if a problem is just in your home or is area wide. Create, manage or cancel repair requests.

Service Troubleshooter
Sometimes you just need more speed. Check for faster speeds in your area.

Faster Speeds