With Starlink Speed ​​Fusion, the upload speed doesn't exceed 1 Mbps. Can anyone help me?

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With Starlink Speed ​​Fusion, the upload speed doesn’t exceed 1 Mbps. Can anyone help me?

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There were certain Starlink ethernet adapters that did not play nicely with some routers, check that the MTU setting on the WAN port you are using is set to 1500.

After that, this may sound stupid but put any gigabit switch you have around between the Peplink router and the Starlink. The incompatibility is with how Starlink implemented a certain ethernet chip, this tends to fix the problem. It’s also an easy thing to test.

Another quick test you can try if you don’t have a switch around and your Peplink router (you didn’t specify a model) supports WIFI WAN, try connecting to the dish through the Starlink access point/router that came with the kit, or the mini has it built in.

You can also enable Starlink for that WAN port on the Network tab, WAN, Starlink at the bottom

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Honestly, no idea if this will help at all but it does let the router get additional errors and log them.

I am assuming that the problem is actually all traffic over the Starlink, if your upload is around 12-30Mbit without speedfusion in play and only tanks with data over the tunnel you have something odd going on. If this is the case, check the CPU usage, make sure you aren’t pegging 1 core somehow? A crazy % of lost packets might do something like this, test your packet loss not through the tunnel with https://speed.cloudflare.com/

Past these suggestions we are going to need a bit more info. Model and HW version and firmware of Peplink, what gen Starlink, what plan. What your throughput is direct to a desktop pc, through the Peplink but not through a speedfusion tunnel. I probably won’t be a lot more help, my Starlinks are on cold standby, found them too unpredictable, installed some DSL connections and 60Ghz backhaul to my primary site instead.

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Hi Kovlin,

Thank you again for all the suggestions.

I would like to provide an update after further testing.

Setup:

  • Router: Peplink B One
  • Firmware: Latest available version installed
  • Starlink: Starlink Mini
  • Plan: Residential Lite
  • Connection: Tested both via Ethernet (WAN) and Wi-Fi WAN
  • Additional WAN: 4G connection used for failover/bonding

Key observations:

  • Direct connection (Starlink → laptop):
    Upload is stable around 30–36 Mbps.

  • Peplink without SpeedFusion:
    Performance remains normal and stable.

  • SpeedFusion (Cloud) enabled:
    Upload drops significantly to around 1–5 Mbps, consistently.

Important additional findings:

  • SpeedFusion works perfectly when using:

    • 4G connection
    • Mobile hotspot (Wi-Fi)

  • Starlink also works perfectly in normal mode (without SpeedFusion).

New real-world tests:

  • I tested SRT streaming at 4–6 Mbps:

    • Over Wi-Fi WAN → stable
    • Over Ethernet WAN (Starlink) → also stable

  • In both cases, the stream runs perfectly with no interruptions, even though SpeedFusion shows low upload values.

  • However, when testing RTMP to Facebook, the connection is noticeably less stable compared to SRT.

Additional tests performed:

  • MTU set to 1500 → no change
  • Different smoothing settings (High → Normal/Off)
  • Health check using ping (8.8.8.8 / 9.9.9.9)
  • Full reset and reconfiguration
  • Tested both Wi-Fi WAN and Ethernet WAN

:arrow_right: The issue persists even when using Ethernet WAN (not Wi-Fi).

Current understanding:

  • The problem only appears when traffic goes through the SpeedFusion Cloud tunnel with Starlink.

  • It does not occur:

    • with Starlink alone
    • with SpeedFusion over 4G or mobile hotspot

This suggests either:

  • a limitation or behavior specific to SpeedFusion Cloud when used with Starlink, or
  • a lower-level compatibility issue between Starlink Mini and the tunnel handling

Current status:

Despite the low reported upload, real SRT streaming works reliably at 4–6 Mbps, which is my main use case (live sports production).

Next step:

I will test adding a gigabit switch between Starlink and the Peplink router, as suggested.

Any additional insights from users running Starlink Mini with SpeedFusion would be greatly appreciated.

Thanks again for your help.

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So, I personally don’t see this problem (triple WAN: cable, Starlink on 100mbps lite, cellular).

I think it’d be really helpful to have screenshots of your SpeedFusion setup. From the local router web UI:

SF Connect → Client Mode → [Your SFC peer] → a screenshot per tunnel

Then let’s get a screenshot during your test:

Status → SpeedFusion VPN → [the graph button on the tunnel you’re testing]

Note, I’d strip out the identifying information at the top right of that page. There is also an export button since that web page can be bigger than what a normal screenshot can capture.

That should help people better understand your setup.

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