My router is not giving me the expected download/upload speed, when running a speedtest. How should I troubleshoot this?

We receive cases from customers on a regular basis informing us that Peplink units they purchased can’t achieve the Internet (WAN) throughput they expect to see.

There are various criteria that influence the Peplink router performance (one or more can be applicable).

To identify and isolate the problem follow the steps below:

1. Data Plan/Bandwidth subscribed

  • You need to know the correct upload and download bandwidth for your internet connection.

  • If you are not sure about this, you will have to contact the ISP to get this information

2. Choose the right model with sufficient horse power (router throughput)

  • Every router model supports a different throughput, make sure the router model supports the throughput you expect to achieve.

  • The router throughput information can be checked on our official website

  • For example, you are using a Peplink Balance 20 and decided to upgrade your internet connection to a connection supporting 300 Mbps down and 300 Mbps upload speeds.

  • You won’t be able to fully utilize your internet connection because the Peplink Balance 20 does not support such high router throughput. You might need to invest in a bigger router model.

3. Correct way to perform Internet/WAN bandwidth test
Step 3a

  • Please make sure your Peplink router has the latest firmware version.

  • Please make sure the WAN link download and upload bandwidth are set correctly.

  • Please make sure the outbound policy is set correctly for the test device; the recommended way is to use a ENFORCED policy. i.e you need to force the traffic from the test device to go out to the internet using the WAN link that you would like to test.

  • Please make sure you do not configure QoS to limit the download or upload speeds.

Step 3b

  • When you perform the speedtest, please make sure the test device is plugged directly into the Peplink router, additional switches and/or hubs can result in unexpected results.

  • The following diagram will not provide an accurate speedtest result, because it is possible that 3rd party devices are the bottleneck; slowing down the speedtest.

  • If there are devices along the way, please bypass all the 3rd party devices and connect directly to Peplink router and perform the speedtest again

  • If you connect directly to Peplink router and still do not able to get the expected bandwidth, proceed to Step 3c

Step 3c

  • Prepare a laptop for testing purposes.

  • Disconnect the cable from Peplink router’s WAN port.

  • Connect the cable from the ISP router directly to the laptop, bypassing the Peplink router.

  • Configure the laptop with the correct IP information.

  • Perform the speedtest. Make sure you are using the same speedtest website and select the same speedtest server.

  • Record the speedtest result

  • If the laptop cannot get the expected speedtest results, report the issue to your internet provider.

  • If the laptop can get the expected speedtest results, proceed to Step 3d

Step 3d

  • If you are using wireless connection to perform the speedtest, please use wired LAN to perform the speedtest instead.

  • If you are using wired LAN and are still unable to get the expected bandwidth, proceed to Step 4

4. Physical port compatibility issue
Step 4a

  • We need to isolate the port compatibility issue

  • Please fix the speed and duplex settings in Peplink router and the ISP router

    • Peplink router WAN - Fix 1Gbps Full Duplex without the “Advertise Speed” box ticked

    • ISP router - Fix 1Gbps Full Duplex on LAN port

  • Then, perform the speedtest again

  • If you are still not able to get the expected bandwidth, proceed to Step 4b

Step 4b

  • Prepare a layer 2 switch

  • Change the speed and duplex settings back to Auto-Negotiation for both devices

  • Put the layer 2 switch in between the Peplink router’s WAN port and the ISP router

  • Perform the speedtest again

5. What to do next if all the above has been verified and the issue still persists ?

  • Open up a support ticket containing the following information:
    • Has the configuration worked in the past or this a new configuration?

    • Have any changes been made recently to the Peplink devices or on your network in general?

    • What is the subscribed total download/upload bandwidth from the ISP ?

    • Does the router deployed in your network support the correct router throughput ?

    • When you connect directly to Peplink router, what is the download and upload bandwidth obtained ?

    • When you connect directly to the ISP router, what is the download and upload bandwidth obtained ?

    • If you perform speedtest using wired WAN, what is the download and upload bandwidth obtained ?

    • If you fix the port speed/duplex at both devices, does this solve the issue ? What is the download and upload bandwidth obtained ?

    • If you place a layer 2 switch in between the Peplink router and the ISP router, does this solve the issue ? What is the download and upload bandwidth obtained ?

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