Any TCP connection needs traffic in both directions; even if you are just downloading, the client has to upload the request and the acknowledge packets. So, there is definitely traffic flowing in both directions.
I think you should post the config files on the OpenWrt router.
fwiw, I've never tried this with Mediatek SoC, but if you want a wireless bridge, see whether section 9.10 and 9.12 (Untick Rebind Protection setting?) in the Install PDF for HH5A is any help: https://openwrt.ebilan.co.uk/viewtopic.php?f=7&t=266
fwiw, I just reset a spare HH5A (atheros wifi) to openwrt defaults, then changed LAN IP address and scan/joined my 5 GHz wifi network just like your original first post. No other changes. No problem with upload speeds when I run speed tests.
Installed very latest 19.07 snapshots r10605. No problems with speeds
hmm, your issue may be specific to Mediatek SoC and/or C50v4 ?
Have you tried connecting to a different wifi router?
What is the RX/TX speeds reported in LuCI > Status > Overview > Associated Stations for the wireless connection to your router?
Only other suggestion is to use 'iperf3' running on two computers.
Each one connected on each side of the wireless link and see if speed is still poor in one direction.
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?
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.
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!
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.
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.