Hey, there! Recently I bought a new router and installed OpenWrt on it. Now my internet download speed via powerline is much slower (upload still fine).
Promised internet speed: 100 Mbit/s down, 10 Mbit/s up speedtest.net result on old router via powerline: >90 Mbit/s down, >10 Mbit/s up speedtest.net result on new router via powerline: <40 Mbit/s down, >10 Mbit/s up
(For comparison: The computer directly connected to the new router via LAN even gets 105 MBit/s and my phone gets ca. 80 MBit/s via 5 GHz too.)
Old router: Netgear WNR2200 with stock firmware
New router: TP-Link Archer A7 with OpenWrt 21.02.1
I'm using the same Windows 10 computer for the speed measurement.
The computer is connected to the new router via the same powerline adapters as before.
In the meantime I connected my TV via an additional powerline adapter (same brand and product as the others) but during the measurement the TV was turned off.
Before my switch to OpenWrt, the TV was connected to the internet via WiFi.
I did not try out the powerline speed on the new router with its stock firmware because I want to keep using OpenWrt.
You have not mentioned make & model of powerline adapters.
Are the powerline adapters plugged directly into wall socket?
Powerline systems are susceptible to electrical noise. Perhaps the A7's power adapter is electrically noisier ?
Can you move the powerline adapter to another wall socket on other side of the room?
Install your WNR2200 between the Archer A7 and the powerline adapter. You may need to change the LAN IP address of the WNR2200. eg. use 192.168.111.1. Set the WAN to use 'DHCP'.
Assuming the Windows 10 computers is wired by ethernet to another powerline adapter located in another room, run a speed test to see if there is any improvement.
All powerline adapters are from TP-Link. On their label it says "TL-PA4010 (AV600)". They're plugged directly into the wall socket.
I'm currently wainting for an Ethernet-USB adapter to be delivered so that I can measure the internet speed with my laptop via different wall sockets and setups. (The other computer is a desktop PC that I can't move around.)
@bill888 I was unable to get the WNR2200 to work between the Archer A7 and the powerline adapter.
I performed multiple measurements with different powerline adapters, different cables and two different laptops and various different wall sockets in different rooms. However, I never got more than 40 Mbit/s
Does laptop work in configuration below to verify WNR2200 is daisy chained to A7 router's LAN port ?
Internet === Archer A7 === WNR2200 === laptop ethernet
Make sure WNR2200 is set up to use DHCP for wan connection, and remember to change its LAN IP address (eg. 192.168.3.1)
Something else you can try?
reinstate the WNR2200 as your main router. Check power line speeds.
Turn on the Archer A7 (not connected to internet or anything else). See if power line speed through WNR2200 falls due to electrical interference from A7 or A7 power adapter when you turn the powerline adapters off and on.
Ensure WNR2200 and A7 use same AC mains power outlet.
Sorry for my extremely late response, I simply forgot about this. I didn't get the configuration
Internet === Archer A7 === WNR2200 === laptop ethernet
to work, but I was able to test the powerline speed with the new modem from my ISP (a Vodafone Station CGA4233DE). Even the connection through TWO power strips connected to the AC sockets enabled speeds of up to 92 Mbit/s.
Internet === Vodafone Station === Ethernet adapter === power strip === AC outlet === powerline === AC outlet === power strip === Ethernet adapter === laptop
During the test, the Archer A7 was not connected to the powerline via an adapter, if that's of any relevance. Also, I used the same AC outlets for the Vodafone Station as for the Archer A7.
However, I was in fact able to make the WNR2200 work again and also tried my TP-Link WR940N (stock firmware) from another floor. Here are a few tests I performed. FAIL means the connection was slower than 40 Mbit/s. PASS means over 90 Mbit/s. (There was nothing in between.)
WNR2200 between Archer A7 and Powerline
FAIL: Vodafone Station === Archer A7 === WNR2200 === Powerline
WR940N between Archer A7 and Powerline
FAIL: Vodafone Station === Archer A7 === WR940N === Powerline
WNR2200 between Archer A7 and laptop
FAIL: Vodafone Station === Archer A7 === WNR2200 === laptop
WR940N between Archer A7 and laptop
FAIL: Vodafone Station === Archer A7 === WR940N === laptop
Laptop directly in Archer A7
PASS: Vodafone Station === Archer A7 === laptop
WR940N instead of Archer A7
PASS: Vodafone Station === WR940N === powerline
If the Archer A7 causes electrical interference, then why does it only occur when a specific type of device (router) or the powerline is connected – and not when a laptop is connected?
Could OpenWrt on the Archer A7 be misconfigured in some way so that, for some obscure reason, it limits the internet speed of connected networks, but not of end devices?
FAIL: Vodafone Station === Archer A7 === WNR2200 === laptop
FAIL: Vodafone Station === Archer A7 === WR940N === laptop
Were these two tests in last post completed over ethernet?
ie. NOT using wifi
I was speculating whether it may be electrical interference. Not a factor given you are seeing slow speed when powerline adapters are not in circuit as shown above.
Is packet steering and software flow offloading enabled on the openwrt devices?
no test result for
Vodafone Station === Archer A7 === Powerline
Unfortunately, that made it actually worse. Before enabling both options, I got at least ~40 Mbit/s, with them enabled barely 30 Mbit/s. It doesn't matter whether I activate both or only one of them, the result is always the same.
I was thinking if you were using all the devices in regular 'router' mode, you may encounter problems if the same subnet (eg. 192.168.x.??) is used on both WAN and LAN ports of a router device.
eg. Not recommended.
Vodafone (LAN IP=192.168.0.1) === (WAN 192.168.0.z) example router (LAN 192.168.0.1) ===
I'm out of ideas.
Clearly a 'compatibility' issue somewhere perhaps causing packet loss.
Perhaps could try 19.07 but that's clutching at straws....
I'm afraid only remaining unhelpful suggestion is don't use openwrt on A7 with powerline adapters....
Yeah, it seems like it's a systematic issue. Thank you for your help, though!
Well, I actually found an acceptable work-around for my specific use case. Now, instead of the Archer A7 the Vodafone Station provides Internet via Powerline to the WR940N upstairs. In order to still block ads in the WR940N's network, it uses the Archer A7's OpenWrt (which has the adblock package installed) as its DNS server: How to use OpenWrt as DNS from different network?
