[KKappa]

I have a pair of ubiquiti devices(powerbeam m2)
First is connected to lan port of archer, other to a laptop
They are working as a wds bridge so my laptop sees the same network no matter if connected directly to archer or through that wireless bridge.

The problem is, transferring files in LAN through the bridge works as expected(almost 100mbps because these devices have only 100 ethernet) but connection with internet is slow, around 15mbps, if i increase quality of wireless link it goes up a little.

I suspect the router does something so the wireless link has to send many small packets so connection is slower than expected but i'm not sure. Anyway, pings are good, there's no packet loss but max speed is low.

And i know it's routers fault because i temporarily replaced archer with another router(without dd-wrt) and internet connection through link was fast, as expected

[KKappa]

Upgraded to r47381 (before i had a version from march), also restored default settings, didn't help.

[d33b0_n4p41m]

You're using a 100Mbit/s wireless bridge connecting to a gigabit switch and expecting full throughput which likely is not going to happen. Did you try setting your laptop ethernet adapter to forced 100Mbit/s full duplex and test the speed directly wired to the Archer C7 v4? Is SFE turned on? We have no idea of your overall configuration on the Archer or your ISP advertised bandwidth up/down.

[KKappa]

I just tried and in fact it's slow! So it's not the wireless bridge, just lack of gigabit ethernet
My internet connection is 50/5 and through 100mbps lan i got 20/5 on speedtest.net, but copying files over lan goes still as expected, 98mbps in task manager.

SFE=Shortcut Forwarding Engine? It was enabled and after disabling it there is no difference.
I tried to enable stp too, no difference.

Also as i said, if i substitute archer with another router i have(tenda ac11, it has gigabit switch too) speedtest goes as expected, around 53 mbps even over 100mb ethernet

Also i said, i tried to restore defaults, connect it to isp's router which is set as a bridge so it acts like a modem
And the problem is still there so its not because of my changes in config

[d33b0_n4p41m]

Did you test with full gigabit link from LAN and get better results? I see no reason that the hardware of the C7 v4 being unable to handle a 50/5 connection, though.

[servicetech]

[d33b0_n4p41m]

^^^^ Something I *totally* forgot about Good catch @servicetech!

[KKappa]

My isps router/modem assigns dynamic ip, there's no authentication(it's cable internet). Problem exists when isp device is set in any mode(both router and bridge).
If isp's device is in router mode and i plug 100mbps ethernet directly, there's no problem. 53mbps on speedtest.

Also i got a new router(archer ax90). There's no problem too if i plug 100mbps ethernet there


Today i configured the problematic router in client bridge mode, first radio connected to ax90, second in access point. Problem still exists when i connect via 100ethernet to this router. Speedtest around 20mbps.
But when i connect to the same router via 1gbit i get normal speed again. Even when i connect via wifi with 65mbps rate i get 40mbps on speedtest so as expected.

So 3 other routers can handle this situation, but archer c7 with dd-wrt can't.

MTU was set to 1500 and largest pings which can pass without fragmentation are 1472. Tried lowering by 100 to 1000, no difference.

I tried basically every option in gui and still can't fix this bastard... Also i used "tcp optimizer" which applied "optimal" settings on my laptop just to see what's going to happen and it actually improved things a little, now i get few mbps more on speedtest.

[KKappa]

Just flashed stock firmware, and it works good so it's something related to dd-wrt


Openwrt works too! But i don't really want to use it, i try to interact with raw linux as little as possible because even simple problems can become a nightmare there 😁

[d33b0_n4p41m]

Now I am curious if this has anything to do with the DSCP quirk that affected speeds on Broadcom routers:

https://svn.dd-wrt.com/ticket/2996