TP-Link Archer C50 V4 Upload Speed Issue - Almost 0 Mbps

I've removed the mac address lines but unfortunately it didn't change anything. The upload speed is still moving around 0.2Mbps.

Connecting to the same WiFi network directly from other devices results in upload speed of around 80Mpbs though.

@bill888 @eduperez do you have any other ideas about what settings I could possibly try changing? I really can't think of anything else. Perhaps a different version of OpenWrt could help?

Thanks a lot for your help!

Some ideas:

Do you see same behaviour on both 2.4 and 5 GHz wifi?

Is it possible to connect c50v4 to a different model wireless router?

Did you use iperf as suggested earlier to test just the transfer speed across just the wireless link to the C50v4?

ie. install iperf3 on PC1. Connect PC1 to LAN port of your main router. Install iperf3 on PC2. Connect PC2 to LAN port of C50v4. Run iperf3 speed test across the wireless link.

You could perhaps try latest development snapshot. Remember to install LuCI package.

If problem persists, you may have discovered a bug.

(I don't own a C50v4 any more, so cannot test.)

Thanks @bill888, unfortunately I don't have another router that I could try connecting to.

I've tried iperf3 and the speed was only about 2Mbps. This I believe explains the slow upload.

I've had the latest snapshot (without LuCI) installed before and had the same issue.

If there's nothing else, I'm going to need to flash original firmware and return the c50v4. This upload speed issue is super strange though, seems like this is the only case of this around!

What do you think?

Perhaps there's a much better supported router around a similar price point? There are so many I really can't tell which one would be best.

In general though, what I need:

  • Strong WiFi connection so I get very good signal when connecting wirelessly to the host network

  • Strong enough WiFi to cover my whole flat (c50v4 is also struggling at this)

Any ideas?

TBH, I don't own any other Mediatek based routers, so can't comment on slow upload issue. I've never witnessed it on old Atheros based routers I own.

Unfortunately, I cannot remember for certain whether I tested 'pseudo bridge' mode (see earlier post) when I did briefly own a C50v4 last summer. I think I did test it but any test would not have been for more than 15 minutes to see how it compared to my Home Hub 5A operating in same mode connecting wirelessly to my main wifi network. But I could be wrong.

The open source wifi drivers used in OpenWrt will always be inferior to closed source wifi drivers included in OEM firmwares. I'm no expert but I don't think the Mediatek wifi drivers are as mature as ath9k and ath10k which have been around for far longer.

The C50 is a low cost router at end of the day. Have you considered spending a bit more money and buying an off the shelf mesh system such as Tenda MW3 if it is available in your country if coverage is more important than speed?

Otherwise, you may have to look in the 'Hardware Questions & Recommendations' sub-forum for further advice on hardware.

Alright, I'm going to restore and return it and find another device.

Is this still the correct process for restoring factory firmware (Support for Archer c50 v4)?

Just want to be sure I do it correctly. I'd really appreciate it if you could just let me know if this is the way.

Thanks a lot for all your help and comments so far!

You wrote, you can connect to the web via WiFi. How ? Only possible on 5GHz, as 2.4 is disabled. And you configured 5GHz both as AP_and_ STA. Which will not work. As I understand, you want to use 5GHz as upstream connection (wan), so neds to be STA. And 2.4GHz as AP, to connect to clients.

My computer is connected to the c50v4 via ethernet. The 5GHz radio is used in station/client mode to connect to the target wireless network.

To be sure I've not accidentally misconfigured things, I've reset the c50v4 back to defaults using the reset button and then followed this guide:

Internet works fine but the issue is the upload speed which is still around 1 to 2Mbps max.

NOTE: I've followed all the guides I could find, including using relayd but nothing at all helped with the upload speed. All other devices connected to the same target wireless network have good upload speeds when tested.

Latest snapshot firmware gives me the same results.

I can't think of anything else I can try. Do you see anything else that might be wrong?

You are (trying to) use 5GHz both as STA and AP. This does not work.
Just to be setup as a STA for the upstream WiFi, using its credentials (encryption/password) .

Apologies for any confusion. Here's the very latest configuration (which only uses the 5GHz radio to connect to target network and using which I can connect to internet from my computer connected via ethernet):


config wifi-device 'radio0'
	option type 'mac80211'
	option channel '11'
	option hwmode '11g'
	option path 'platform/10300000.wmac'
	option htmode 'HT20'
	option disabled '1'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

config wifi-device 'radio1'
	option type 'mac80211'
	option channel '44'
	option hwmode '11a'
	option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
	option htmode 'VHT80'

config wifi-iface 'default_radio1'
	option device 'radio1'
	option network 'wan'
	option ssid 'THE_SSID'
	option encryption 'psk2'
	option mode 'sta'
	option key 'THE_PASSWORD'

config interface 'loopback'
	option ifname 'lo'
	option proto 'static'
	option ipaddr ''
	option netmask ''

config globals 'globals'
	option ula_prefix 'fd6e:1691:0876::/48'

config interface 'lan'
	option type 'bridge'
	option ifname 'eth0.1'
	option proto 'static'
	option ipaddr ''
	option netmask ''
	option ip6assign '60'

config device 'lan_dev'
	option name 'eth0.1'
	option macaddr '98:da:c4:e1:70:95'

config interface 'wan'
	option proto 'dhcp'

config device 'wan_dev'
	option name 'eth0.2'
	option macaddr '98:da:c4:e1:70:96'

config interface 'wan6'
	option ifname 'eth0.2'
	option proto 'dhcpv6'

config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'

config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '1 2 3 4 6t'

config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '0 6t'

It's all default config and I've only made the changes in the ' Using MASQUERADE' part of the 'Routed Client' guide linked above.

Do I need to do something else?

Now your WiFi settings look reasonable.
As 5GHz on Mediatek chipset is seldom used, I would not rule out a possible bug here.
Having no immediate ideas any more, I would do the same as alrady suggested, to connect to upstream via LAN. And then check the speed again.
BTW: Whats the ping time to ?

The ping to is 13ms. Unfortunately, I can't connect via LAN as I only have wireless access.

How could we check the firmware to see if it's a bug? Is there someone who'd be able to check it easily?

ping is within expected range. Return path (download) is fast, which is in contrast to your experience.
Just a wild guess: Do you have SQM enabled, by chance ?
If yes, disable, reboot and check upload speed.
(SQM throttles uploads, by purpose. But might be misconfigured.).

I don't remember seeing SQM anywhere - where would I find this? I've gone through all settings and don't see it.

Somewhere in LuCI.
Can not say any more, as I practically never use LuCI, sorry.

Looks like it's an extra set of scripts:

I'm happy to check via SSH.

Yes, @Tibit windows instructions is what I used for removing header from OEM firmware for reverting my Archer C50v4 (EU) version from OpenWrt to OEM firmware.

Perfect, thanks! I've restored it to factory firmware and returned.

I'll open another thread to figure out the best router to get instead - I've been reading the forum for hours but still can't decide what I need to get.

@bill888 @reinerotto @eduperez here's the new thread - Powerful Wireless Bridge - Which router?

If you do have any suggestions, I'd really appreciate it!

fwiw, sorry for bumping old thread.

I tested relayd with 19.07.1 on RT-AC57U (MT7621AT) and I can reproduce very poor upload speed with 5 GHz link too.

I reported my findings in this thread where another user with Xiaomi 3G (MT7621) sees same problem.

Looks like it is a Mediatek specific issue?

I don't see this issue with EA6350 v3 (IPQ4018) or Home Hub 5A (Lantiq/Atheros wifi)

Bug Report FS#2816