Speed issues with 388.1

[iraweissman]

Hi All. Have a 1GB fiber connection that connections with PPPoE. Connection dropped a few days ago, and of course when the ISP said it wasn't their issue, I went into tinker mode which led me to discover the update to 388.1. I updated. Eventually internet came back - turned out it actually was a problem on the ISP's side. After the internet came back, my speed as reported by Speedtest on my desktop (connected via Ethernet through an AiMesh node (with ethernet backhaul) dropped by about half. I figured maybe the drop in speed was related to the outage and I'd give it a few days.

Speed didn't return, so I thought maybe I'll downgrade the firmware and see what happens. And lo and behold, speeds jumped again. The high end after the downgrade is around 800 Mbps - acceptable for a 1Gb connection. But while using 388.1, the reported speed was always between 300 and 500.

Speedtest from the router's GUI always shows around 300-500 - with both firmware versions. I'm chalking this up to the router based speedtest being unreliable.

QoS is off in both firmware versions.

Did I uncover a bug?

(btw, I've run iperf3 to test the speeds between the router and my desktop and it was about 950 Mbps.)

 

[iraweissman]

I will add that there was one difference in addition to the upgrade to 388.1 - I set up a Wireguard connection. I neglected to test 388.1 without Wireguard in use. Of course - I wasn't testing anything on a device that was actually using the VPN. I'm just saying that the router was maintaining an active VPN connection which I suspect could in theory have an effect on overall speed if it was sucking resources away from the processor.

 

[iraweissman]

Ok, I just saw this in the release notes:

WireGuard
The biggest user-facing change is the introduction of WireGuard support as an alternative VPN protocol. This implementation is developped by Asus, the only changes made were to integrate it with VPN Director (which is Asuswrt-Merlin's alternative to VPN Fusion), and to integrate it into the web interface (as we don't use Asus' VPN Fusion management interface). Note that while supported, I don't intend to make any major changes to the WireGuard implementation, as my development focus will remain with OpenVPN. One important limitation to note is that WireGuard requires NAT acceleration to be disabled, which greatly reduces its usefulness on a router, as if you have a fast enough WAN connection to truly benefit from WireGuard performance, that performance ceiling will most likely cap at around 300-350 Mbps due to the lack of NAT acceleration for your router's traffic.

I'm assuming this was my issue.

 

[iraweissman]

Ok, and now confirmed this was it. Re-installed 388.1 and disabled Wireguard. Speeds back. Sorry to waste anyone's time, but I'm guessing it's worth it to leave this thread up in case someone else has the same issue.

 

[Viktor Jaep]

Glad we could be of assistance, @iraweissman! LOL