Low throughput, limited to 300Mbps on a 600Mbps connection

Hello, a few days ago I installed a community build for my Comfast CF-E538AC access point. I got it all up and running, with all links set to 1000Mbps and two Wi-Fi networks configured.

However, when I connect either by using 5GHz WiFi or in the Ethernet port of the AP, I cannot get past 300Mbps. The original stock firmware could reach 600Mbps (the limit of my connection) when using the RJ45 port, but now I cannot.

The full specsheet of the AP is here https://openwrt.org/toh/hwdata/comfast/comfast_cf-e538ac

¿Any tips to fix this? ¿How could I troubleshoot this problem?

Do you have the same issue with an official build?

  • Does it have NAT offload?
  • Did you enable it?
  • To be clear, are you referring to the displayed WiFi bandwidth or actual speed results?
  • You won't get 600 Mbps on this device with the processor it has (I understand OEM did this)

(I'm really not sure if you're referring to WiFi bandwidth or actual speed results...let's clear up that point first.)

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Thanks for helping! I will try to answer all your questions.

There is no official build for this device, I installed the one that can be found at https://forum.openwrt.org/t/tracking-down-regression-led-cf-e538ac/79717/8

I do not know how to check if it has NAT offload or where can I find the settings to enable it.
I am referring to speed results from speedtest.net using WiFi, but I also have the problem when connected via Ethernet cable.

Yes, the stock firmware could reach 600Mbps when connected to the RJ45 port, and the device is advertised as a "1200Mbps AP". It is a Comfast CF-E538AC.

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This is acting as a dumb ap or as a router?

NAT is not relevant for an AP but wifi driver. Support cartainly is. Wifi drivers from mfgs often have tweaks not available to the public is my impression

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It is acting as a dumb AP right now. I disabled the firewall, DNS and DHCP.

so nat speed is not the issue, the issue is probably wifi drivers, and that's probably not fixable because the mfg doesn't release the info.


Did you check the channel width for 5G

Those are bad news :frowning:
I hope that when an official release for my device comes up it is more tweaked, for the time being I can use the AP just with 300Mbps.

I did not, but the problem also happens when connected to the Ethernet port, which is not related with wireless connectivity.

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Well that's not wifi drivers, can you explain about this further. What's the topology you are working with here?

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I have the WiFi adapters bridged with the back port (which is connected to the router) and then the front port connects with the back port via a VLAN using the switch chip. It really seems that it is a processor issue, because the manufacturer may have applied some tweaks that vanilla OpenWRT does not have.

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Hmm I'm not sure about this device but if there is a switch chip there is no need for a cpu bridge, just have the front port and back port on the same vlan and let the switch chip do it's job

That is how I have it configured. The bridge is for connecting the wireless adapters, not for Ethernet.

Hi, I have the exact same problem with Redmi ac2100...